Bicyclic compounds and their use in medicine, process for their preparation and pharmaceutical compositions containing them

ABSTRACT

Compounds of formula (I)                    
     its tautomeric forms, its stereoisomers, its polymorphs, its pharmaceutically acceptable salts or its pharmaceutically acceptable solvates can be used to prevent or treat diabetes caused by insulin resistance or impaired glucose tolerance or complications of diabetes caused by insulin resistance or impaired glucose tolerance. The compounds can also be used to reduce cholesterol, body weight, blood glucose, triglycerides and free fatty acids in the blood.

FIELD OF THE INVENTION

The present invention relates to novel antiobesity and hypocholesterolemic compounds, their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates and pharmaceutically acceptable compositions containing them. More particularly, the present invention relates to novel β-aryl-α-oxysubstituted alkylcarboxylic acids of the general formula (I), their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates and pharmaceutically acceptable compositions containing them.

The present invention also relates to a process for the preparation of the above said novel compounds, their analogs, their derivatives, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, pharmaceutically acceptable solvates, novel intermediates and pharmaceutical compositions containing them.

The compounds of the present invention lower total cholesterol (TC); increase high density lipoprotein (HDL) and decrease low density lipoprotein (LDL), which have a beneficial effect on coronary heart disease and atherosclerosis.

The compounds of general formula (I) are useful in reducing body weight and for the treatment and/or prophylaxis of diseases such as hypertension, coronary heart disease, atherosclerosis, stroke, peripheral vascular diseases and related disorders. These compounds are useful for the treatment of familial hypercholesterolemia, hypertriglyceridemia, lowering of atherogenic lipoproteins, VLDL (very low density lipoprotein) and LDL. The compounds of the present invention can be used for the treatment of certain renal diseases including glomerulonephritis, glomerulosclerosis, nephrotic syndrome, and hypertensive nephrosclerosis. The compounds of general formula (I) are also useful for the treatment and/or prophylaxis of insulin resistance (type II diabetes), impaired glucose tolerance, dyslipidemia, disorders related to syndrome X such as hypertension, obesity, insulin resistance, coronary heart disease, and other cardiovascular disorders. These compounds may also be useful as aldose reductase inhibitors, for improving cognitive functions in dementia, treating diabetic complications, disorders related to endothelial cell activation, psoriasis, polycystic ovarian syndrome (PCOS) and osteoporosis.

BACKGROUND OF INVENTION

Atherosclerosis and other peripheral vascular diseases are the major causes affecting the quality of life of millions of people. Therefore, considerable attention has been directed towards understanding the etiology of hypercholesterolemia and hyperlipidemia and development of effective therapeutic strategies.

Hypercholesterolemia has been defined as plasma cholesterol level that exceeds arbitrarily defined value called “normal” level. Recently, it has been accepted that “ideal” plasma levels of cholesterol are much below the “normal” level of cholesterol in the general population and the risk of coronary artery disease (CAD) increases as cholesterol level rises above the “optimum” (or “ideal”) value. There is clearly a definite cause and effect-relationship between hypercholesterolemia and CAD, particularly for individuals with multiple risk factors. Most of the cholesterol is present in the esterified forms with various lipoproteins such as Low density lipoprotein (LDL), Intermediate density lipoprotein (IDL), High density lipoprotein (HDL) and partially as Very low density lipoprotein (VLDL). Studies clearly indicate that there is an inverse correlationship between CAD and atherosclerosis with serum HDL-cholesterol concentrations. (Stampfer et al., N. Engl. J Med., 325 (1991), 373-381) and the risk of CAD increases with increasing levels of LDL and VLDL.

In CAD, generally “fatty streaks” in carotid, coronary and cerebral arteries, are found which are primarily free and esterified cholesterol. Miller et aL, (Br. Med. J., 282 (1981), 1741-1744) have shown that increase in HDL-particles may decrease the number of sites of stenosis in coronary arteries of human, and high level of HDL-cholesterol may protect against the progression of atherosclerosis. Picardo et al., (Arteriosclerosis 6 (1986) 434-441) have shown by in vitro experiment that HDL is capable of removing cholesterol from cells. They suggest that HDL may deplete tissues of excess free cholesterol and transfer them to liver (Macikinnon et al., J Biol. chem. 261 (1986), 2548-2552). Therefore, agents that increase HDL cholesterol would have therapeutic significance for the treatment of hypercholesterolemia and coronary heart diseases (CHD).

Obesity is a disease highly prevalent in affluent societies and in the developing world and is a major cause of morbidity and mortality. It is a state of excess body fat accumulation. The causes of obesity are unclear. It is believed to be of genetic origin or promoted by an interaction between the genotype and environment. Irrespective of the cause, the result is fat deposition due to imbalance between the energy intake versus energy expenditure. Dieting, exercise and appetite suppression have been a part of obesity treatment. There is a need for efficient therapy to fight this disease since it may lead to coronary heart disease, diabetes, stroke, hyperlipidemia, gout, osteoarthritis, reduced fertility and many other psychological and social problems.

Diabetes and insulin resistance is yet another disease which severely effects the quality of a large population in the world. Insulin resistance is the diminished ability of insulin to exert its biological action across a broad range of concentrations. In insulin resistance, the body secretes abnormally high amounts of insulin to compensate for this defect; failing which, the plasma glucose concentration inevitably rises and develops into diabetes. Among the developed countries, diabetes mellitus is a common problem and is associated with a variety of abnormalities including obesity, hypertension, hyperlipidemia (J. Clin. Invest., (1985) 75: 809-817; N. Engl. J. Med. (1987) 317: 350-357; J. Clin. Endocrinol. Metab., (1988) 66: 580-583; J. Clin. Invest., (1975) 68: 957-969) and other renal complications (See Patent Application No. WO 95/21608). It is now increasingly being recognized that insulin resistance and relative hyperinsulinemia have a contributory role in obesity, hypertension, atherosclerosis and type 2 diabetes mellitus. The association of insulin resistance with obesity, hypertension and angina has been described as a syndrome having insulin resistance as the central pathogenic link-Syndrome-X.

Hyperlipidemia is the primary cause for cardiovascular (CVD) and other peripheral vascular diseases. High risk of CVD is related to the higher LDL (Low Density Lipoprotein) and VLDL (Very Low Density Lipoprotein) seen in hyperlipidemia. Patients having glucose intolerance/insulin resistance in addition to hyperlipidemia have higher risk of CVD. Numerous studies in the past have shown that lowering of plasma triglycerides and total cholesterol, in particular LDL and VLDL and increasing HDL cholesterol help in preventing cardiovascular diseases.

Peroxisome proliferator activated receptors (PPAR) are members of the nuclear receptor super family. The gamma (γ) isoform of PPAR (PPARγ) has been implicated in regulating differentiation of adipocytes (Endocrinology, (1994) 135: 798-800) and energy homeostasis (Cell, (1995) 83: 803-812), whereas the alpha (α) isoform of PPAR (PPARα) mediates fatty acid oxidation (Trend. Endocrin. Metab., (1993) 4: 291-296) thereby resulting in reduction of circulating free fatty acid in plasma (Current Biol. (1995) 5: 618-621). PPARA agonists have been found useful for the treatment of obesity (WO 97/36579). It has been recently disclosed that there exists synergism for the molecules, which are agonists for both PPARα and PPARγ and suggested to be useful for the treatment of syndrome X (WO 97/25042). Similar synergism between the insulin sensitizer (PPARγ agonist) and HMG CoA reductase inhibitor has been observed which may be useful for the treatment of atherosclerosis and xanthoma. (EP 0 753 298).

A few β-aryl-α-hydroxy propionic acids their derivatives and their analogs have been reported to be useful in the treatment of hyperglycemia and hypercholesterolemia. Some of such compounds described in the prior art are outlined below:

i) U.S. Pat. No. 5,306,726; WO 91/19702 disclose several 3-aryl-2-hydroxypropionic acid derivatives of general formulas (IIa) and (IIb) as hypolipidemic and hypoglycemic agents.

Examples of these compounds are shown in formulas (IIc) and (IId)

ii) Intenational Patent Applications, WO 95/03038 and WO 96/04260 disclose compounds of formula (IIe)

wherein R^(a) represents 2-benzoxazolyl or 2-pyridyl and R^(b) represent CF₃, CH₂OCH₃ or CH₃. A typical example is (S)-3-[4-[2-[N-(2-benzoxazolyl)-N-methylamino]ethoxy]phenyl]-2-(2,2,2-trifluoroethoxy)propanoic acid (IIf).

iii) International Patent Application Nos. WO 94/13650, WO 94/01420 and WO 95/17394 disclose the compounds of general formula (IIg)

A¹—X—(CH₂)_(n)—O—A²—A³—Y.R²  (IIg)

wherein A¹ represents aromatic heterocycle, A² represents substituted benzene ring and A³ represents a moiety of formula (CH₂)_(m)—CH—(OR¹), wherein R¹ represents alkyl groups, m is an integer; X represents substituted or unsubstituted N; Y represents C═O or C═S; R² represents OR³ where R³ may be alkyl, aralkyl, or aryl group; n represents an integer in the range of 2-6. An example of these compounds is shown in formula (IIh)

SUMMARY OF THE INVENTION

With an objective to develop novel compounds for lowering cholesterol and reducing body weight with beneficial effects in the treatment and/or prophylaxis of diseases related to increased levels of lipids, atherosclerosis, coronary artery diseases, Syndrome-X, impaired glucose tolerance, insulin resistance, insulin resistance leading to type 2 diabetes and diabetes complications thereof, for the treatment of diseases wherein insulin resistance is the pathophysiological mechanism, for the treatment of hypertension, atherosclerosis and coronary artery diseases with better efficacy, potency and lower toxicity, we focussed our research to develop new compounds effective in the treatment of the above mentioned diseases. Effort in this direction has led to compounds having general formula (I).

The main objective of the present invention is therefore, to provide novel β-aryl-α-oxysubstituted alkylcarboxylic acids, their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates and pharmaceutical compositions containing them, or their mixtures.

Another objective of the present invention is to provide novel β-aryl-α-oxysubstituted alkylcarboxylic acids, their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates and pharmaceutical compositions containing them or their mixtures which may have agonist activity against PPARα and/or PPARγ, and optionally inhibit HMG CoA reductase, in addition to agonist activity against PPARα and/or PPARγ.

Another objective of the present invention is to provide novel β-aryl-α-oxysubstituted alkylcarboxylic acids, their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates and pharmaceutical compositions containing them or their mixtures having enhanced activities, without toxic effect or with reduced toxic effect.

Yet another objective of the present invention is a process for the preparation of novel β-aryl-α-oxysubstituted alkylcarboxylic acids of formula (I), their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts and their pharmaceutically acceptable solvates.

Still another objective of the present invention is to provide pharmaceutical compositions containing compounds of the general formula (I), their analogs, their derivatives, their tautomers, their stereoisomers, their polymorphs, their salts, solvates or their mixtures in combination with suitable carriers, solvents, diluents and other media normally employed in preparing such compositions.

Another objective of the present invention is to provide novel intermediates, a process for their preparation and use of the intermediates in processes for preparation of β-aryl-α-oxysubstituted alkyl carboxylic acids of formula (I), their derivatives, their analogs, their tautomers, their stereoisomers, their polymorphs, their salts and their pharmaceutically acceptable solvates.

DETAILED DESCRIPTION OF THE INVENTION

α-Oxysubstituted propionic acids, their derivatives and their analogs of the present invention have the general formula (I)

where the groups R¹, R², R³, R⁴, and the groups R⁵ and R⁶ when attached to a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, acyl, acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino, aralkoxycarbonylamino, carboxylic acid or its derivatives, or sulfonic acid or its derivatives; one or both of R⁵ and R⁶ may also represent an oxo group when they are attached to a carbon atom; R⁵ and R⁶ when attached to a nitrogen atom represents hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl, heteroaryl, heteroaralkyl, acyl, acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy, heteroaralkoxy, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, carboxylic acid derivatives, or sulfonic acid derivatives; X represents a heteroatom selected from oxygen, sulfur or NR¹¹ where R¹¹ is selected from hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, acyl, alkoxycarbonyl, aryloxycarbonyl, or aralkoxycarbonyl groups; Ar represents an optionally substituted divalent single or fused aromatic or heterocyclic group; R⁷ represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, optionally substituted aralkyl group or forms a bond together with the adjacent group R⁸; R⁸ represents hydrogen, hydroxy, alkoxy, halogen, lower alkyl group, acyl, or optionally substituted aralkyl or R⁸ forms a bond together with R⁷; R⁹ represents hydrogen, or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acyl, heterocyclyl, heteroaryl, or heteroaralkyl groups; R¹⁰ represents hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroaralkyl groups; Y represents oxygen or NR¹², where R¹² represents hydrogen, alkyl, aryl, hydroxyalkyl, aralkyl, heterocyclyl, heteroaryl, or heteroaralkyl groups; R¹⁰ and R¹² together may form a 5 or 6 membered cyclic structure containing carbon atoms, which may optionally contain one or more heteroatoms selected from oxygen, sulfur or nitrogen; the linking group represented by —CH₂)_(n)—(O)_(m)— may be attached either through a nitrogen atom or a carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or 1.

Suitable groups represented by R¹-R⁴ and the groups R⁵ and R⁶ when attached to carbon atom, may be selected from hydrogen, halogen atom such as fluorine, chlorine, bromine, or iodine; hydroxy, cyano, nitro, formyl; substituted or unsubstituted (C₁-C₁₂)alkyl group, especially, linear or branched (C₁-C₆)alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, t-butyl, n-pentyl, isopentyl, hexyl and the like; cyclo(C₃-C₆)alkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like, the cycloalkyl group may be substituted; cyclo(C₃-C₆)alkoxy group such as cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy and the like, the cycloalkoxy group may be substituted; aryl group such as phenyl or naphthyl, the aryl group may be substituted; aralkyl such as benzyl or phenethyl, C₆H₅CH₂CH₂CH₂, naphthylmethyl and the like, the aralkyl group may be substituted and the substituted aralkyl is a group such as CH₃C₆H₄CH₂, Hal-C₆H₄CH₂, CH₃OC₆H₄CH₂, CH₃OC₆H₄CH₂ CH₂ and the like; heteroaryl group such as pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, benzofuranyl and the like, the heteroaryl group may be substituted; heterocyclyl groups such as aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl, piperazinyl and the like, the heterocyclyl group may be substituted; aralkoxy group such as benzyloxy, phenethyloxy, naphthyhmethyloxy, phenylpropyloxy and the like, the aralkoxy group may be substituted; heteroaralkyl group such as furanmethyl, pyridinemethyl, oxazolemethyl, oxazolethyl and the like, the heteroaralkyl group may be substituted; aralkylamino group such as C₆H₅CH₂NH, C₆H₅CH₂CH₂NH, C₆H₅CH₂NCH₃ and the like, which may be substituted; alkoxycarbonyl such as methoxycarbonyl, ethoxycarbonyl and the like, which may be substituted; aryloxycarbonyl group such as optionally substituted phenoxycarbonyl, naphthyloxycarbonyl and the like; aralkoxycarbonyl group such as benzyloxycarbonyl, phenethyloxycarbonyl, naphthylmethoxycarbonyl and the like, which may be substituted; (C₁-C₆)alkylamino group such as NHCH₃, NHC₂H₅, NHC₃H₇, NHC₆H₁₃, and the like, which may be substituted; (C₁-C₆)dialkylamino group such as N(CH₃)₂, NCH₃(C₂H₅), N(C₂H₅)₂ and the like, which may be substituted; alkoxyalkyl group such as methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl and the like, which may be substituted; aryloxyalkyl group such as C₆H₅OCH₂, C₆H₅OCH₂CH₂, naphthyloxymethyl and the like, which may be substituted; aralkoxyalkyl group such as C₆H₅CH₂OCH₂, C₆H₅CH₂OCH₂CH₂ and the like, which may be substituted; heteroaryloxy and heteroaralkoxy, wherein heteroaryl moiety is as defined earlier and may be substituted; aryloxy group such as phenoxy, naphthyloxy and the like, the aryloxy group may be substituted; arylamino group such as HNC₆H₅, NCH₃(C₆H₅), NHC₆H₄CH₃, NHC₆H₄-Hal and the like, which may be substituted; amino group which may be substituted; amino(C₁-C₆)alkyl which may be substituted; hydroxy(C₁-C₆)alkyl which may be substituted; (C₁-C₆)alkoxy such as methoxy, ethoxy, propyloxy, butyloxy, iso-propyloxy and the like, which may be substituted; thio(C₁-C₆)alkyl which may be substituted; (C₁-C₆)alkylthio which may be substituted; acyl group such as acetyl, propionyl or benzoyl and the like, the acyl group may be substituted; acylamino groups such as NHCOCH₃, NHCOC₂H₅, NHCOC₃H₇, NHCOC₆H₅ and the like, which may be substituted; aralkoxycarbonylamino group such as NHCOOCH₂C₆H₅, NHCOOCH₂CH₂C₆H₅, N(CH₃)COOCH₂C₆H₅, N(C₂H₅)COOCH₂C₆H₅, NHCOOCH₂C₆H₄CH₃, NHCOOCH₂C₆H₄OCH₃ and the like, which may be substituted; aryloxycarbonylamino group such as NHCOOC₆H₅, NHCOOC₆H₅, NCH₃COOC₆H₅, NC₂H₅COOC₆H₅, NHCOOC₆H₄, CH₃, NHCOOC₆H₄OCH₃ and the like, which may be substituted; alkoxycarbonylamino group such as NHCOOC₂H₅, NHCOOCH₃ and the like, which may be substituted; carboxylic acid or its derivatives such as amides, like CONH₂, CONHMe, CONMe₂, CONHEt, CONEt₂, CONHPh and the like, the carboxylic acid derivatives may be substituted; acyloxy group such as OOCMe, OOCEt, OOCPh and the like, which may be substituted; sulfonic acid or its derivatives such as SO₂NH₂, SO₂NHMe, SO₂NMe₂, SO₂NHCF₃ and the like, the sulfonic acid derivatives may be substituted. One or both of R⁵ and R⁶ may also represent an oxo group.

When the groups represented by R¹-R⁴ and the groups R⁵ and R⁶ when attached to carbon atom are substituted, the substituents may be selected from halogen, hydroxy, or nitro or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aralkoxy, aryl, aralkyl, aralkoxyalkyl, heterocyclyl, heteroaryl, heteroaralkyl, acyl, acyloxy, hydroxyalkyl, amino, acylamino, arylamino, aminoalkyl, aryloxy, alkoxycarbonyl, alkylamino, alkoxyalkyl, alkylthio, thioalkyl groups, carboxylic acid or its derivatives, or sulfonic acid or its derivatives .

It is preferred that the substituents on R¹-R⁶ represent halogen atom such as fluorine, chlorine, bromine; alkyl group such as methyl, ethyl, isopropyl, n-propyl, n-butyl; cycloalkyl group such as cyclopropyl; aryl group such as phenyl; aralkyl group such as benzyl; (C₁-C₃)alkoxy, benzyloxy, hydroxy group, acyl or acyloxy groups.

Suitable R⁵ and R⁶ when attached to nitrogen atom is selected from hydrogen, hydroxy, formyl; substituted or unsubstituted (C₁-C₁₂)alkyl group, especially, linear or branched (C₁-C₆)alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, t-butyl, n-pentyl, isopentyl, hexyl and the like; cyclo(C₃-C₆)alkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like, the cycloalkyl group may be substituted; cyclo(C₃-C₆)alkyloxy group such as cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy and the like, the cycloalkoxy group may be substituted; aryl group such as phenyl, naphthyl and the like, the aryl group may be substituted; aralkyl such as benzyl or phenethyl, C₆H₅CH₂CH₂CH₂, naphthylmethyl and the like, the aralkyl group may be substituted and the substituted aralkyl is a group such as CH₃C₆H₄CH₂, Hal-C₆H₄CH₂, CH₃OC₆H₄CH₂, CH₃OC₆H₄CH₂CH₂ and the like; heteroaryl group such as pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, benzofuranyl and the like, the heteroaryl group may be substituted; heterocyclyl groups such as aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl, piperazinyl and the like, the heterocyclyl group may be substituted; aralkoxy group such as benzyloxy, phenethyloxy, naphthylmethyloxy, phenylpropyloxy and the like, the aralkoxy group may be substituted; heteroaralkyl group such as furanmethyl, pyridinemethyl, oxazolemethyl, oxazolethyl and the like, the heteroaralkyl group may be substituted; aralkylamino group such as C₆H₅CH₂NH, C₆H₅CH₂CH₂NH, C₆H₅CH₂NCH₃ and the like, which may be substituted; alkoxycarbonyl such as methoxycarbonyl, ethoxycarbonyl and the like, which may be substituted; aryloxycarbonyl group such as optionally substituted phenoxycarbonyl, naphthyloxycarbonyl and the like; aralkoxycarbonyl group such as benzyloxycarbonyl, phenethyloxycarbonyl, naphthylmethoxycarbonyl and the like, which may be substituted; (C₁-C₆)alkylamino group such as NHCH₃, N(CH₃)₂, NCH₃(C₂H₅), NHC₂H₅, NHC₃H₇, NHC₆H₁₃ and the like, which may be substituted; alkoxyalkyl group such as methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl and the like, which may be substituted; aryloxyalkyl group such as C₆H₅OCH₂, C₆H₅OCH₂CH₂, naphthyloxymethyl and the like, which may be substituted; aralkoxyalkyl group such as C₆H₅CH₂OCH₂, C₆H₅CH₂OCH₂CH₂ and the like, which may be substituted; heteroaryloxy and heteroaralkoxy, wherein heteroaryl moiety is as defined earlier and may be substituted; aryloxy group such as phenoxy, naphthyloxy and the like, the aryloxy group may be substituted; arylamino group such as HNC₆H₅, NCH₃(C₆H₅), NHC₆H₄CH₃, NHC₆H₄-Hal and the like, which may be substituted; amino group which may be substituted; amino(C₁-C₆)alkyl which may be substituted; hydroxy(C₁-C₆)alkyl which may be substituted; (C₁-C₆)alkoxy such as methoxy, ethoxy, propyloxy, butyloxy, iso-propyloxy and the like, which may be substituted; thio(C₁-C₆)alkyl which may be substituted; (C₁-C₆)alkylthio which may be substituted; acyl group such as acetyl, propionyl, benzoyl and the like, the acyl group may be substituted; acylamino groups such as NHCOCH₃, NHCOC₂H₅, NHCOC₃H₇, NHCOC₆H₅ and the like, which may be substituted; carboxylic acid derivatives such as amides, like CONH₂, CONHMe, CONMe₂, CONHEt, CONEt₂, CONHPh and the like, the carboxylic acid derivatives may be substituted; acyloxy group such as OOCMe, OOCEt, OOCPh and the like, which may be substituted; sulfonic acid derivatives such as SO₂NH₂, SO₂NHMe, SO₂NMe₂, SO₂NHCF₃ and the like, the sulfonic acid derivatives may be substituted.

When the groups represented by R⁵ and R⁶ attached to nitrogen are substituted, preferred substituents may be selected from halogen such as fluorine, chlorine; hydroxy, acyl, acyloxy, or amino groups.

Suitable X includes oxygen, sulfur or a group NR¹¹ as defined above, preferably oxygen and sulfur. Suitably R¹¹ represent hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, aryl group such as phenyl or naphthyl, aralkyl group such as benzyl or phenethyl; acyl group such as acetyl, propanoyl, butyroyl, benzoyl and the like; (C₁-C₆)alkoxycarbonyl; aryloxycarbonyl such as phenoxycarbonyl, CH₃OC₆H₄OCO, Hal-C₆H₄OCO, CH₃C₆H₄OCO, naphthyloxycarbonyl and the like; aralkoxycarbonyl such as benzyloxycarbonyl, phenethyloxycarbonyl and the like; the groups represented by R¹¹ may be substituted or unsubstituted. When the groups represented by R¹¹ are substituted, the substituents may be selected from halogen, optionally halogenated lower alkyl, hydroxy, and optionally halogenated (C₁-C₃)alkoxy groups.

It is preferred that the group represented by Ar be substituted or unsubstituted groups selected from divalent phenylene, naphthylene, pyridyl, quinolinyl, benzofuranyl, dihydrobenzofuryl, benzopyranyl, dihydrobenzopyranyl, indolyl, indolinyl, azaindolyl, azaindolinyl, pyrazolyl, benzothiazolyl, benzoxazolyl and the like. The substituents on the group represented by Ar may be selected from linear or branched optionally halogenated (C₁-C₆)alkyl, optionally halogenated (C₁-C₃)alkoxy, halogen, acyl, amino, acylamino, thio or carboxylic or sulfonic acids and their derivatives.

It is more preferred that Ar represents a substituted or unsubstituted divalent, phenylene, naphthylene, benzofuranyl, indolyl, indolinyl, quinolinyl, azaindolyl, azaindolinyl, benzothiazolyl or benzoxazolyl groups.

It is still more preferred that Ar is represented by divalent phenylene or benzofuranyl, which may be optionally substituted by methyl, halomethyl, methoxy or halomethoxy groups.

Suitable R⁷ includes hydrogen, lower alkyl groups such as methyl, ethyl or propyl; hydroxy, (C₁-C₃)alkoxy; halogen atom such as fluorine, chlorine, bromine, iodine; aralkyl such as benzyl, phenethyl, which may be optionally substituted or R⁷ together with R⁸ represents a bond.

Suitable R⁸ may be hydrogen, lower alkyl groups such as methyl, ethyl or propyl; hydroxy, (C₁-C₃)alkoxy; halogen atom such as fluorine, chlorine, bromine, iodine; acyl group such as linear or branched (C₂-C₁₀)acyl group such as acetyl, propanoyl, butanoyl, pentanoyl, benzoyl and the like; aralkyl such as benzyl, phenethyl, which may be optionally substituted or together with R⁷ forms a bond.

Suitable groups represented by R⁹ may be selected from hydrogen, linear or branched (C₁-C₁₆)alkyl, preferably (C₁-C₁₂)alkyl group such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, pentyl, hexyl, octyl and the like; (C₃-C₇)cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like, the cycloalkyl group may be substituted; aryl group such as phenyl, naphthyl, the aryl group may be substituted; heteroaryl group such as pyridyl, thienyl, furyl and the like, the heteroaryl group may be substituted; heteroaralkyl group such as furanmethyl, pyridinemethyl, oxazolemethyl, oxazolethyl and the like, the heteroaralkyl group may be substituted; aralkyl group such as benzyl and phenethyl and the like, wherein the alkyl moiety may contain C₁-C₆ atoms, wherein the aryl moiety may be substituted; heterocyclyl group such as aziridinyl, pyrrolidinyl, piperidinyl and the like, the heterocyclyl group may be substituted; (C₁-C₆)alkoxy(C₁-C₆)alkyl group such as methoxymethyl, ethoxymethyl, methoxyethyl, ethoxypropyl and the like, the alkoxyalkyl group may be substituted; linear or branched (C₂-C₁₆)acyl group such as acetyl, propanoyl, butanoyl, benzoyl, octanoyl, decanoyl and the like, which may be substituted; (C₁-C₆)alkoxycarbonyl, the alkyl group may be substituted; aryloxycarbonyl such as phenoxycarbonyl, naphthyloxycarbonyl and the like, the aryl group may be substituted; (C₁-C₆)alkylaminocarbonyl, the alkyl group may be substituted; arylaminocarbonyl such as PhNHCO, naphthylaminocarbonyl and the like, the aryl moiety may be substituted. The substituents may be selected from halogen, hydroxy, or nitro or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, aralkoxyalkyl, heterocyclyl, heteroaryl, heteroaralkyl, acyl, acyloxy, hydroxyalkyl, amino, acylamino, arylamino, aminoalkyl, aryloxy, alkoxycarbonyl, alkylamino, alkoxyalkyl, alkylthio, thioalkyl groups, carboxylic acid or its derivatives, or sulfonic acid or its derivatives.

Suitable groups represented by R¹⁰ may be selected from hydrogen, linear or branched (C₁-C₁₆)alkyl, preferably (C₁-C₁₂)alkyl group such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, pentyl, hexyl, octyl and the like; (C₃-C₇)cycloalkyl such as cyclopropyl, cyclopentyl, cyclohexyl and the like, the cycloalkyl group may be substituted; aryl group such as phenyl, naphthyl and the like, the aryl group may be substituted; heteroaryl group such as pyridyl, thienyl, furyl and the like, the heteroaryl group may be substituted; heteroaralkyl group such as furanmethyl, pyridinemethyl, oxazolemethyl, oxazolethyl and the like, the heteroaralkyl group may be substituted; aralkyl group such as benzyl and phenethyl and the like, the aralkyl group may be substituted; and heterocyclyl group such as aziridinyl, pyrrolidinyl, piperidinyl and the like, the heterocyclyl group may be substituted. The substituents on R¹⁰ may be selected from the same group of R¹-R⁶.

Suitable groups represented by R¹² may be selected from hydrogen, linear or branched (C₁-C₁₆)alkyl, preferably (C₁-C₁₂)alkyl; hydroxy(C₁-C₆)alkyl; aryl group such as phenyl, naphthyl and the like; aralkyl group such as benzyl, phenethyl and the like; heterocyclyl group such as aziridinyl, pyrrolidinyl, piperidinyl, and the like; heteroaryl group such as pyridyl, thienyl, furyl and the like; and heteroaralkyl group such as furanmethyl, pyridinemethyl, oxazolemethyl, oxazolethyl and the like.

Suitable ring structures formed by R¹⁰ and R¹² together may be selected from pyrrolidinyl, piperidinyl, morpholinyl, pipeazinyl and the like.

Suitable m is an integer ranging from 0-1. It is preferred that when m=0, Ar represents a divalent benzofuranyl, benzoxazolyl, benzothiazolyl, indolyl, indolinyl, dihydrobenzofuryl, or dihydrobenzopyranyl group and when m=1, Ar represents a substituted or unsubstituted groups selected from divalent phenylene, naphthylene, pyridyl, quinolinyl, benzofuranyl, dihydrobenzofuryl, benzopyranyl, dihydrobenzopyranyl, indolyl, indolinyl, azaindolyl, azaindolinyl, pyrazolyl, benzothiazolyl, benzoxazolyl and the like.

Suitable n is an integer ranging from 1 to 4, preferably n represents an integer 1 or 2.

It is preferred that when m=1, n represents 2.

It is also preferred that when m=0, n represents 1.

Pharmaceutically acceptable salts forming part of this invention include salts of the carboxylic acid moiety such as alkali metal salts like Li, Na, and K salts, alkaline earth metal salts like Ca and Mg salts, salts of organic bases such as lysine, arginine, guanidine, diethanolamine, choline and the like, ammonium or substituted ammonium salts, and aluminum salts. Salts may include acid addition salts where appropriate which are, sulphates, nitrates, phosphates, perchlorates, borates, hydrohalides, acetates, tartrates, maleates, citrates, succinates, palmoates, methanesulphonates, benzoates, salicylates, hydroxynaphthoates, benzenesulfonates, ascorbates, glycerophosphates, ketoglutarates and the like. Pharmaceutically acceptable solvates may be hydrates or comprising other solvents of crystallization such as alcohols.

Particularly useful compounds according to the present invention include:

Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropenoate;

(±) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(+) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(−) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

Ethyl (E/Z)-3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropenoate;

Ethyl (E/Z-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropenoate;

(±) Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoate;

(+) Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoate;

(−) Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoate;

(±) Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(+) Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(−) Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(±) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(+) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(−) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(±) Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(+) Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(−) Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

Ethyl (E/Z)-3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropenoate;

(±) Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(+) Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(−) Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

Ethyl (E/Z)-3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropenoate;

(±) Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoate;

(+) Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoate;

(−) Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoate;

Ethyl 3-[4-[2-(2,3dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate;

Ethyl 3-[4-[2-(2,3dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate;

Ethyl 3-[4-[2-(2,3dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxpropanoate;

Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoate;

Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxy propanoate;

Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropenoate;

(±) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(+) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(−) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl ethoxy]phenyl]-2-phenoxypropenoate;

(±) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(+) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(−) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

Ethyl (E/Z)-3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropenoate;

(±) Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate;

(+) Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate;

(−) Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate;

Ethyl (E/Z)-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropenoate;

(±) Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate;

(+) Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate;

(−) Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate;

(±) 3-[4-[2(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[4-[2(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid salts;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(±) 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts;

(+) 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts;

(−) 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts;

(±) 3-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts;

(+) 3-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts;

(−) 3-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(±) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(+) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(−) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(±) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(+) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(−) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(±) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(+) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(−) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(±) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(+) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

(−) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide;

2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

2-(2-Fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(±) 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(−) 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(±) 3-[4-[2-(3-Oxo-2H-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[4-[2-(3-Oxo-2H-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(−) 3-[4-[2-(3-Oxo-2H-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(±) 3-[6-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[6-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts;

(−) 3-[6-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts;

(±) 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts;

(−) 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoic acid and its salts;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoic acid and its salts;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid and its salts;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid and its salts;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoic acid and its salts;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoic acid and its salts;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(±) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid its salts;

(−) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(±) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(+) Methyl 2-methyl-3-[4-[2-(2,3dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(−) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(±) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(+) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(−) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(±) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(+) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(−) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate;

(±) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoic acid and its salts;

(+) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoic acid and its salts;

(−) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoic acid and its salts;

(±) 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate;

(+) 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate;

(−) 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate;

(±) 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid and its salts;

(−) 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid and its salts;

(±) 4-Nitrophenyl-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxy phenyl]-2-ethoxypropanoate;

(+) 4-Nitrophenyl-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxy phenyl]-2-ethoxypropanoate; and

(−) 4-Nitrophenyl-3-[4-(4-benzyl-3 ,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxy phenyl]-2-ethoxypropanoate.

According to a feature of the present invention, the compound of general formula (I) where R⁷ and R⁸ together represent a bond, Y represents oxygen atom, R¹, R², R³, R⁴, R⁵, R⁶, R⁹, R¹⁰, X, n, m and Ar are as defined earlier, can be prepared by any of the following routes shown in Scheme I.

Route (1): The reaction of a compound of the general formula (IIIa) where all symbols are as defined earlier with a compound of formula (IIIb) where R⁹, R¹⁰ are as defined earlier and R¹⁴ represents (C₁-C₆)alkyl, to yield compound of general formula (I) where R⁷, R⁸ together represent a bond and Y represents an oxygen atom may be carried out neat in the presence of a base such as alkali metal hydrides like NaH, or KH or organolithiums like CH₃Li, BuLi and the like or alkoxides such as NaOMe, NaOEt, K⁺BuO⁻ or mixtures thereof The reaction may be carried out in the presence of solvents such as THF, dioxane, DMF, DMSO, DME and the like or mixtures thereof. HMPA may be used as cosolvent. The reaction temperature may range from −78° C. to 50° C., preferably at a temperature in the range of −10° C. to 30° C. The reaction is more effective under anhydrous conditions. The compound of general formula (IIIb) may be prepared according to the procedure described in the literature (Annalen. Chemie, (1996) 53, 699).

Route (2): The reaction of a compound of general formula (IIIc) where all symbols are as defined earlier with a compound of general formula (IIId) where R⁷, R⁸ together represent a bond and all symbols are as defined earlier and L¹ is a leaving group such as halogen atom, p-toluenesulfonate, methanesulfonate, trifluoromethanesulfonate and the like, preferably a halogen atom to produce a compound of general formula (I) defined above may be carried out in the presence of solvents such as DMSO, DMF, DME, THF, dioxane, ether and the like or a combination thereof. The reaction may be carried out in an inert atmosphere which may be maintained by using inert gases such as N₂, Ar, or He. The reaction may be effected in the presence of a base such as alkalis like sodium hydroxide, or potassium hydroxide; alkali metal carbonates like sodium carbonate, or potassium carbonate; alkali metal hydrides such as sodium hydride or potassium hydride; organometallic bases like n-butyl lithium; alkali metal amides like sodamide or mixtures thereof. The amount of base may range from 1 to 5 equivalents, based on the amount of the compound of formula (IIIc), preferably the amount of base ranges from 1 to 3 equivalents. Phase transfer catalysts such as tetraalkylammonium halide or hydroxide may be added. The reaction may be carried out at a temperature in the range of 0° C. to 150° C., preferably at a temperature in the range of 15° C. to 100° C. The duration of the reaction may range from 0.25 to 48 hours, preferably from 0.25 to 12 hours.

Route (3): The reaction of a compound of formula (IIIe) where all symbols are as defined earlier with a compound of formula (IIIf) where R⁹=R¹⁰ and are as defined earlier, to produce a compound of the formula (I) where R⁷ and R⁸ together represent a bond may be carried out neat in the presence of a base such as alkali metal hydrides like NaH, KH or organolithiums like CH₃Li, BuLi and the like or alkoxides such as NaOMe, NaOEt, K⁺BuO⁻ and the like or mixtures thereof. The reaction may be carried out in the presence of aprotic solvents such as THF, dioxane, DMF, DMSO, DME and the like or mixtures thereof. HMPA may be used as cosolvent. The reaction temperature may range from −78° C. to 100° C., preferably at a temperature in the range of −10° C. to 50° C.

Route (4): The reaction of a compound of the general formula (IIIa) where all other symbols are as defined earlier, with a compound of formula (IIIg) where R⁸ represents hydrogen atom, R⁹ and R¹⁰ are as defined earlier may be carried out in the presence of a base. The nature of the base is not critical. Any base normally employed for aldol condensation reaction may be employed; bases like metal hydride such as NaH, or KH, metal alkoxides such as NaOMe, K⁺BuO⁻, or NaOEt, metal amides such as LiNH₂, or LiN(ipr)₂ may be used. Aprotic solvent such as THF, ether, or dioxane may be used. The reaction may be carried out in an inert atmosphere which may be maintained by using inert gases such as N₂, Ar, or He and the reaction is more effective under anhydrous conditions. Temperature in the range of −80° C. to 35° C. may be used. The β-hydroxy product initially produced may be dehydrated under conventional dehydration conditions such as treating with PTSA in solvents such as benzene or toluene. The nature of solvent and dehydrating agent is not critical. Temperature in the range of 20° C. to reflux temperature of the solvent used may be employed, preferably at reflux temperature of the solvent by continuous removal of water using a Dean Stark water separator.

Route (5): The reaction of compound of formula (IIIh) where all symbols are as defined earlier and L¹ represents a leaving group such as as halogen atom, p-toluenesulfonate, methanesulfonate, trifluoromethanesulfonate and the like with a compound of formula (IIIi) where R⁷ and R⁸ together represent a bond and R⁹, R¹⁰ and Ar are as defined earlier to produce a compound of the formula (I) where m=1 and all other symbols are as defined above may be carried out in the presence of aprotic solvents such as THF, DMF, DMSO, DME and the like or mixtures thereof. The reaction may be carried out in an inert atmosphere which may be maintained by using inert gases such as N₂, Ar, or He. The reaction may be effected in the presence of a base such as K₂CO₃, Na₂CO₃ or NaH or mixtures thereof Acetone may be used as solvent when Na₂CO₃ or K₂CO₃ is used as a base. The reaction temperature may range from 0° C.-120° C., preferably at a temperature in the range of 30° C.-100° C. The duration of the reaction may range from 1 to 24 hours, preferably from 2 to 12 hours. The compound of formula (IIIi) can be prepared according to known procedures by a Wittig Horner reaction between the hydroxy protected aryl aldehyde such as benzyloxyaryl aldehyde and compound of formula (IIIb), followed by deprotection.

Route (6): The reaction of compound of general formula (IIIj) where all symbols are as defined earlier with a compound of general formula (IIIi) where R⁷ and R⁸ together represent a bond and R⁹, R¹⁰ and Ar are as defined earlier to produce a compound of the formula (I) where m=1 and all other symbols are as defined above may be carried out using suitable coupling agents such as dicyclohexyl urea, triarylphosphine/dialkylazadicarboxylate such as PPh₃/DEAD and the like. The reaction may be carried out in the presence of solvents such as THF, DME, CH₂Cl₂, CHCl₃, toluene, acetonitrile, carbontetrachloride and the like. The inert atmosphere may be maintained by using inert gases such as N₂, Ar, or He. The reaction may be effected in the presence of DMAP, HOBT and they may be used in the range of 0.05 to 2 equivalents, preferably 0.25 to 1 equivalents. The reaction temperature may be in the range of 0° C. to 100° C., preferably at a temperature in the range of 20° C. to 80° C. The duration of the reaction may range from 0.5 to 24 hours, preferably from 6 to 12 hours.

In yet another embodiment of the present invention, the compound of the general formula (I) where R¹, R², R³, R⁴, R⁵, R⁶, R⁹, R¹⁰, X, n, m, R⁷ represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, optionally substituted aralkyl group, R⁸ represents hydrogen, hydroxy, alkoxy, halogen, lower alkyl group, acyl or optionally substituted aralkyl and Ar are as defined earlier and Y represents oxygen can be prepared by one or more of the processes shown in Scheme-II:

Route 7: The reduction of compound of the formula (IVa) which represents a compound of formula (I) where R⁷ and R⁸ together represent a bond and Y represents an oxygen atom and all other symbols are as defined earlier, obtained as described earlier (Scheme-I), to yield a compound of the general formula (I) where R⁷ and R⁸ each represent a hydrogen atom and all symbols are as defined earlier, may be carried out in the presence of gaseous hydrogen and a catalyst such as Pd/C, Rh/C, Pt/C, and the like. Mixtures of catalysts may be used. The reaction may also be conducted in the presence of solvents such as dioxane, acetic acid, ethyl acetate and the like. A pressure between atmospheric pressure and 80 psi may be employed. The catalyst may be preferably 5-10% Pd/C and the amount of catalyst used may range from 50-300% w/w. The reaction may also be carried out by employing metal solvent reduction such as magnesium in alcohol or sodium amalgam in alcohol, preferably methanol. The hydrogenation may be carried out in the presence of metal catalysts containing chiral ligands to obtain a compound of formula (I) in optically active form. The metal catalyst may contain rhodium, ruthenium, indium and the like. The chiral ligands may preferably be chiral phosphines such as (2S,3S)-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)ethane, 1,2-bis(2-methoxyphenyl phenylphosphino)ethane, (−)-2,3-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino) butane and the like. Any suitable chiral catalyst may be employed which would give required optical purity of the product (I) (Ref: Principles of Asymmetric Synthesis, Tet. Org. Chem. Series Vol 14, pp311-316, Ed. Baldwin J. E.).

Route 8: The reaction of compound of formula (IVb) where all symbols are as defined earlier and L² is a leaving group such as halogen atom with an alcohol of general formula (IVc), where R⁹ is as defined earlier to produce a compound of the formula (I) defined earlier may be carried out in the presence of solvents such as THF, DMF, DMSO, DME and the like or mixtures thereof. The reaction may be carried out in an inert atmosphere which may be maintained by using inert gases such as N₂, Ar, or He. The reaction may be effected in the presence of a base such as KOH, NaOH, NaOMe, NaOEt, K⁺BuO⁻ or NaH or mixtures thereof. Phase transfer catalysts such as tetraalkylammonium halides or hydroxides may be employed. The reaction temperature may range from 20° C.-120° C., preferably at a temperature in the range of 30° C.-100° C. The duration of the reaction may range from 1 to 12 hours, preferably from 2 to 6 hours. The compound of general formula (IVb) and its preparation has been disclosed in the copending U.S. Application No. 08/982,910.

Route 9: The reaction of compound of formula (IIIh) defined earlier with compound of formula (IIIi) where all symbols are as defined earlier to produce a compound of the formula (I) where m=1 and all other symbols are as defined above, may be carried out in the presence of solvents such as THF, DMF, DMSO, DME and the like or mixtures thereof. The reaction may be carried out in an inert atmosphere which is maintained by using inert gases such as N₂, Ar or He. The reaction may be effected in the presence of a base such as K₂CO₃, Na₂CO₃, NaH or mixtures thereof. Acetone may be used as a solvent when K₂CO₃ or Na₂CO₃ is used as a base. The reaction temperature may range from 20° C.-120° C., preferably at a temperature in the range of 30° C.-80° C. The duration of the reaction may range from 1 to 24 hours, preferably from 2 to 12 hours. The compound of formula (IIIi) may be prepared by Wittig Horner reaction between the protected hydroxyaryl aldehyde and compound of formula (IIIb) followed by reduction of the double bond and deprotection. Alternatively, the compound of formula (IIIi) may be prepared by following a procedure disclosed in WO 94/01420.

Route 10: The reaction of compound of general formula (IIIj) defined earlier with a compound of general formula (IIIi) where all symbols are as defined earlier to produce a compound of the formula (I) where m=1 and all other symbols are as defined above may be carried out using suitable coupling agents such as dicyclohexyl urea, triarylphosphine/dialkylazadicarboxylate such as PPh₃/DEAD and the like. The reaction may be carried out in the presence of solvents such as THF, DME, CH₂Cl₂, CHCl₃, toluene, acetonitrile, carbon tetrachloride and the like. The inert atmosphere may be maintained by using inert gases such as N₂, Ar, or He. The reaction may be effected in the presence of DMAP, HOBT and they may be used in the range of 0.05 to 2 equivalents, preferably 0.25 to 1 equivalents. The reaction temperature may be in the range of 0° C. to 100° C., preferably at a temperature in the range of 20° C. to 80° C. The duration of the reaction may range from 0.5 to 24 hours, preferably from 6 to 12 hours.

Route 11: The reaction of compound of formula (IVd) which represents a compound of formula (I) where R⁹ represents hydrogen atom and all other symbols are as defined earlier with a compound of formula (IVe) where R⁹ is as defined earlier and L² is a leaving group such as a halogen atom, may be carried out in the presence of solvents such as THF, DMF, DMSO, DME and the like. The inert atmosphere may be maintained by using inert gases such as N₂, Ar or He. The reaction may be effected in the presence of a base such as KOH, NaOH, NaOMe, K⁺BuO⁻, NaH and the like. Phase transfer catalyst such as tetraalkylammonium halides or hydroxides may be employed. The reaction temperature may range from 20° C. to 150° C., preferably at a temperature in the range of 30° C. to 100° C. The duration of the reaction may range from 1 to 24 hours, preferably from 2 to 6 hours.

Route 12: The reaction of a compound of the general formula (IIIa) as defined above with a compound of formula (IIIg) where R⁸, R⁹, and R¹⁰ are as defined earlier may be carried out under conventional conditions. The base is not critical. Any base normally employed for aldol condensation reaction may be employed, metal hydride such as NaH, or KH; metal alkoxides such as NaOMe, K^(t)BuO⁻, or NaOEt; metal amides such as LiNH₂, or LiN(ipr)₂. Aprotic solvent such as THF may be used. Inert atmosphere may be employed such as argon and the reaction is more effective under anhydrous conditions. Temperature in the range of −80° C. to 25° C. may be used. The β-hydroxy aldol product may be dehydroxylated using conventional methods, conveniently by ionic hydrogenation technique such as by treating with a trialkyl silane in the presence of an acid such as trifluoroacetic acid. Solvent such as CH₂Cl₂ may be used. Favorably, the reaction proceeds at 25° C. A higher temperature may be employed if the reaction is slow.

Route 13: The reaction of a compound of general formula (IIIc) where all symbols fill are as defined earlier with a compound of general formula (IIId) where L¹ is a leaving group such as halogen atom, p-toluenesulfonate, methanesulfonate, trifluoromethanesulfonate and the like, preferably L¹ is a halogen atom, and all other symbols are as defined earlier to produce a compound of general formula (I) may be carried out in the presence of solvents such as DMSO, DMF, DME, THF, dioxane, ether and the like or a combination thereof. The reaction may be carried out in an inert atmosphere which may be maintained by using inert gases such as N₂, Ar, or He. The reaction may be effected in the presence of a base such as alkalis like sodium hydroxide, or potassium hydroxide, alkali metal carbonates like sodium carbonate, or potassium carbonate; alkali metal hydrides such as sodium hydride or potassium hydride; organometallic bases like n-butyl lithium, alkali metal amides like sodamide or mixtures thereof The amount of base may range from 1 to 5 equivalents, based on the amount of the compound of formula (IIIc), preferably the amount of base ranges from 1 to 3 equivalents. The reaction may be carried out at a temperature in the range of 0° C. to 150° C., preferably at a temperature in the range of 15° C. to 100° C. The duration of the reaction may range from 0.25 to 24 hours, preferably from 0.25 to 12 hours.

Route 14: The conversion of compound of formula (IVf) to a compound of formula (I) may be carried out either in the presence of base or acid and the selection of base or acid is not critical. Any base normally used for hydrolysis of nitrile to acid may be employed, such as metal hydroxides such as NaOH, or KOH in an aqueous solvent or any acid normally used for hydrolysis of nitrile to ester may be employed such as dry HCl in an excess of alcohol such as methanol, ethanol, propanol etc. The reaction may be carried out at a temperature in the range of 0° C. to reflux temperature of the solvent used, preferably at a temperature in the range of 25° C. to reflux temperature of the solvent used. The duration of the reaction may range from 0.25 to 48 hrs.

Route 15: The reaction of a compound of formula (IVg) where all symbols are as defined earlier with a compound of formula (IVc) where R⁹ is as defined earlier to produce a compound of formula (I) (by a rhodium carbenoid mediated insertion reaction) may be carried out in the presence of rhodium (II) salts such as rhodium (II) acetate. The reaction may be carried out in the presence of solvents such as benzene, toluene, dioxane, ether, ThF and the like or a combination thereof or when practicable in the presence of R⁹OH as solvent at any temperature providing a convenient rate of formation of the required product, generally at an elevated temperature, such as reflux temperature of the solvent. The inert atmosphere may be maintained by using inert gases such as N₂, Ar, or He. The duration of the reaction may range from 0.5 to 24 h, preferably from 0.5 to 6 h.

The compound of general formula (I) where Y represents oxygen and R¹⁰ is as defined earlier may be converted to compound of formula (I), where Y represents NR¹² by reaction with appropriate amines of the formula NHR¹⁰R¹², where R¹⁰ and R¹² are as defined earlier. Suitably the compound of formula (I) where YR¹⁰ represents OH may be converted to acid halide, preferably YR¹⁰=Cl, by reacting with appropriate reagents such as oxalyl chloride, thionyl chloride and the like, followed by treatment with amines. Alternatively, mixed anhydrides may be prepared from compound of formula (I) where YR¹⁰ represents OH and all other symbols are as defined earlier by treating with acid halides such acetyl chloride, acetyl bromide, pivaloyl chloride, dichlorobenzoyl chloride and the like. The reaction may be carried out in the presence of suitable base such as pyridine, triethylamine, diisopropyl ethyl amine and the like. Solvents such as halogenated hydrocarbons like CHCl₃, or CH₂Cl₂; hydrocarbons such as benzene, toluene, xylene and the like may be used. The reaction may be carried out at a temperature in the range of −40° C. to 40° C., preferably at a temperature in the range of 0° C. to 20° C. The acid halide or mixed anhydride thus prepared may further be treated with appropriate amines.

In another embodiment of the present invention the novel intermediate of formula (IVf)

where the groups R¹, R², R³, R⁴, and the groups R⁵ and R⁶ when attached to a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, acyl, acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino, aralkoxycarbonylamino, carboxylic acid or its derivatives, or sulfonic acid or its derivatives; R⁵ and R⁶ when attached to nitrogen atom represents hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl, heteroaryl, heteroaralkyl, acyl, acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy, heteroaralkoxy, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, carboxylic acid derivatives, or sulfonic acid derivatives; one or both of R⁵ and R⁶ may also represent an oxo group when they are attached to carbon atom; X represents a heteroatom selected from oxygen, sulfur or NR¹¹ where R¹¹ is selected from hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, acyl, alkoxycarbonyl, aryloxycarbonyl, or aralkoxycarbonyl groups; Ar represents an optionally substituted divalent single or fused aromatic or heterocyclic group; R⁷ represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, or optionally substituted aralkyl group; R⁸ represents hydrogen, hydroxy, alkoxy, halogen, lower alkyl group, acyl, optionally substituted aralkyl group; R⁹ represents hydrogen, or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acyl, heterocyclyl, heteroaryl, or heteroaralkyl groups; the linking group represented by —(CH₂)_(n)—(O)_(m)— may be attached either through nitrogen atom or carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or 1 and a process for its preparation and its use in the preparation of β-aryl-α-substituted hydroxyalkanoic acids is provided.

The compound of formula (IVf) where R⁷ and R⁸ each represent hydrogen atoms and all other symbols are as defined earlier is prepared by a process outlined in Scheme-III.

The reaction of a compound of formula (IIIa) where all symbols are as defined earlier with a compound of formula (IVh) where R⁹ is as defined earlier and Hal represents a halogen atom such as Cl, Br, or I may be carried out under conventional conditions in the presence of a base. The base is not critical. Any base normally employed for Wittig reaction ma y be employed, metal hydride such as NaH, or KH; metal alkoxides such as NaOMe, K^(t)BuO⁻, or NaOEt; or metal amides such as LiNH₂, or LiN(ipr)₂. Aprotic solvent such as THF, DMSO, dioxane, DME and the like may be used. Mixture of solvents may be used. HMPA may be used as a cosolvent. Inert atmosphere may be employed such as argon and the reaction is more effective under anhydrous conditions. Temperature in the range of −80° C. to 100° C. may be used.

The compound of (IVi) where all symbols are as defined earlier may be converted to a compound of formula (IVj) where R⁷ and R⁸ represent hydrogen atoms and all other symbols are as defined earlier, by treating with an alcohol under anhydrous conditions in the presence of a strong anhydrous s acid such as p-toluenesulfonic acid.

The compound of formula (IVj) define e d above upon treatment with trialkylsilyl cyanide such as trimethylsilyl cyanide produces a compound of formula (IVf) where R⁷ and R⁸ represent hydrogen atoms and all other symbols are as defined

In still another embodiment of the present invention the novel intermediate of formula (IVg)

where the groups R¹, R², R³, R⁴, and the groups R⁵ and R⁶ when attached to a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, acyl, acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino, aralkoxycarbonylamino, carboxylic acid or its derivatives, or sulfonic acid or its derivatives; one or both of R⁵ and R⁶ may also represent an oxo group when they are attached to a carbon atom; R⁵ and R⁶ when attached to a nitrogen atom represents hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl, heteroaryl, heteroaralkyl, acyl, acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy, heteroaralkoxy, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, carboxylic acid derivatives, or sulfonic acid derivatives; X represents a heteroatom selected from oxygen, sulfur or NR¹¹ where R¹¹ is selected from hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, acyl, alkoxycarbonyl, aryloxycarbonyl, or aralkoxycarbonyl groups; Ar represents an optionally substituted divalent single or fused aromatic or heterocyclic group; R⁷ represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, or optionally substituted aralkyl group; R¹⁰ represents hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroaralkyl groups; Y represents oxygen; the linking group represented by —(CH₂)_(n)—(O)_(m)— may be attached either through nitrogen atom or carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or 1 and a process for its preparation and its use in the preparation of β-aryl-α-substituted hydroxyalkanoic acids is provided.

The compound of formula (IVg) where all other symbols are as defined earlier may be prepared by reacting a compound of formula (IVk)

where R⁸ is a hydrogen atom and all other symbols are as defined earlier, with an appropriate diazotizing agent.

The diazotization reaction may be under conventional conditions. A suitable diazotizing agent is an alkyl nitrile, such as iso-amyl nitrile. The reaction may be carried out in presence of solvents such as THF, dioxane, ether, benzene and the like or a combination thereof. Temperature in the range of −50° C. to 80 may be used. The reaction may be carried out in an inert atmosphere which may be maintained by using inert gases such as N₂, Ar or He. The duration of the reaction may range from 1 to 24 h, preferably, 1 to 12 h.

The compound of formula (IVk) may also be prepared by a reaction between (IIIh) where all symbols are as defined earlier and a compound of formula (IVl)

where R⁸ is a hydrogen atom and all other symbols are as defined earlier.

The reaction of compound of formula (IIIh) where all symbols are as defined earlier and a compound of formula (IVl) where all symbols are as defined earlier may be carried out in the presence of solvents such as THF, DMF, DMSO, DME and the like or mixtures thereof. The reaction may be carried out in an inert atmosphere which is maintained by using inert gases such as N₂, Ar or He. The reaction may be effected in the presence of a base such as K₂CO₃, Na₂CO₃ or NaH or mixtures thereof. Acetone may be used as a solvent when K₂CO₃ or Na₂CO₃ is used as a base. The reaction temperature may range from 20° C.-120° C., preferably at a temperature in the range of 30° C.-80° C. The duration of the reaction may range from 1 to 24 hours, preferably from 2 to 12 hours.

As used in this application the term neat means the reaction is carried out without the use of solvent. The pharmaceutically acceptable salts are prepared by reacting the compound of formula (I) with 1 to 4 equivalents of a base such as sodium hydroxide, sodium methoxide, sodium hydride, potassium t-butoxide, calcium hydroxide, magnesium hydroxide and the like, in solvents like ether, THF, methanol, t-butanol, dioxane, isopropanol, ethanol etc. Mixtures of solvents may be used. Organic bases like lysine, arginine, diethanolamine, choline, guanidine and their derivatives etc. may also be used. Alternatively, acid addition salts wherever applicable are prepared by treatment with acids such as hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid, phosphoric acid, p-toluenesulphonic acid, methanesulfonic acid, acetic acid, citric acid, maleic acid, salicylic acid, hydroxynaphthoic acid, ascorbic acid, palmitic acid, succinic acid, benzoic acid, benzenesulfonic acid, tartaric acid and the like in solvents like ethyl acetate, ether, alcohols, acetone, THF, dioxane etc. Mixtures of solvents may also be used.

The stereoisomers of the compounds forming part of this invention may be prepared by using reactants in their single enantiomeric form in the process wherever possible or by conducting the reaction in the presence of reagents or catalysts in their single enantiomer form or by resolving the mixture of stereoisomers by conventional methods. Some of the preferred methods include use of microbial resolution, resolving the diastereomeric salts formed with chiral acids such as mandelic acid, camphorsulfonic acid, tartaric acid, lactic acid, and the like wherever applicable or chiral bases such as brucine, cinchona alkaloids and their derivatives and the like. Commonly used methods are compiled by Jaques et al in “Enantiomers, Racemates and Resolution” (Wiley Interscience, 1981). More specifically the compound of formula (I) where YR¹⁰ represents OH may be converted to a 1:1 mixture of diastereomeric amides by treating with chiral amines, aminoacids, aminoalcohols derived from aminoacids; conventional reaction conditions may be employed to convert acid into an amide; the diastereomers may be separated either by fractional crystallization or chromatography and the stereoisomers of compound of formula (I) may be prepared by hydrolyzing the pure diastereomeric amide.

Various polymorphs of a compound of general formula (I) forming part of this invention may be prepared by crystallization of compound of formula (I) under different conditions. For example, using different solvents commonly used or their mixtures for recrystallization; crystallizations at different temperatures; various modes of cooling, ranging from very fast to very slow cooling during crystallizations. Polymorphs may also be obtained by heating or melting the compound followed by gradual or fast cooling. The presence of polymorphs may be determined by solid probe nmr spectroscopy, ir spectroscopy, differential scanning calorimetry, powder X-ray diffraction or such other techniques.

The present invention also provides pharmaceutical compositions, containing a compounds of the general formula (I), as defined above, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates in combination with the usual pharmaceutically employed carriers, diluents and the like, useful in reducing body weight and for the treatment and/or prophylaxis of diseases such as hypertension, coronary heart disease, atherosclerosis, stroke, peripheral vascular diseases and related disorders. These compounds are useful for the treatment of familial hypercholesterolemia, hypertriglyceridemia, lowering of atherogenic lipoproteins, VLDL and LDL. The compounds of the present invention can be used for the treatment of certain renal diseases including glomerulonephritis, glomerulosclerosis, nephrotic syndrome and hypertensive nephrosclerosis. The compounds of general formula (I) are also useful for the treatment/prophylaxis of insulin resistance (type II diabetes), impaired glucose tolerance, dyslipidemia, disorders related to syndrome X such as hypertension, obesity, insulin resistance, coronary heart disease, and other cardiovascular disorders. These compounds may also be useful as aldose reductase inhibitors, for improving cognitive functions in dementia, treating diabetic complications, disorders related to endothelial cell activation, psoriasis, polycystic ovarian syndrome (PCOS) and osteoporosis.

The pharmaceutical composition may be in the forms normally employed, such as tablets, capsules, powders, syrups, solutions, suspensions and the like, may contain flavorants, sweeteners etc. in suitable solid or liquid carriers or diluents, or in suitable sterile media to form injectable solutions or suspensions. Such compositions typically contain from 1 to 20%, preferably 1 to 10% by weight of active compound, the remainder of the composition being pharmaceutically acceptable carriers, diluents or solvents.

The compound of the formula (I) as defined above are clinically administered to mammals, including man, via either oral or parenteral routes. Administration by the oral route is preferred, being more convenient and avoiding the possible pain and irritation of injection. However, in circumstances where the patient cannot swallow the medication, or absorption following oral administration is impaired, as by disease or other abnormality, it is essential that the drug be administered parenterally. By either route, the dosage is in the range of about 0.01 to about 50 mg/kg body weight of the subject per day or preferably about 0.01 to about 30 mg/kg body weight per day administered singly or as a divided dose. However, the optimum dosage for the individual subject being treated will be determined by the person responsible for treatment, generally smaller doses being administered initially and thereafter increments made to determine the most suitable dosage.

Suitable pharmaceutically acceptable carriers include solid fillers or diluents and sterile aqueous or organic solutions. The active compound will be present in such pharmaceutical compositions in the amounts sufficient to provide the desired dosage in the range as described above. Thus, for oral administration, the compounds can be combined with a suitable solid, liquid carrier or diluent to form capsules, tablets, powders, syrups, solutions, suspensions and the like. The pharmaceutical compositions, may, if desired, contain additional components such as flavorants, sweeteners, excipients and the like. For parenteral administration, the compounds can be combined with sterile aqueous or organic media to form injectable solutions or suspensions. For example, solutions in sesame or peanut oil, aqueous propylene glycol and the like can be used, as well as aqueous solutions of water-soluble pharmaceutically-acceptable acid addition salts or salts with base of the compounds. The injectable solutions prepared in this manner can then be administered intravenously, intraperitoneally, subcutaneously, or intramuscularly, with intramuscular administration being preferred in humans.

The invention is explained in detail in the examples given below which are provided by way of illustration only and therefore should not be construed to limit the scope of the invention.

PREPARATION 1 4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]benzaldehyde

A mixture of 2H-1,4-benzoxazin-3-(4H)-one (1.6 g, 10.7 mmol), 4-(2-bromoethoxy)benzaldehyde (2.95 g, 12.8 mmol) and potassium carbonate (5.93 g, 42.97 mmol) in dry dimethyl formamide (30 mL) was stirred at 80° C. for 10 h. Water (100 mL) was added and extracted with ethyl acetate (2×75 mL). The combined organic layers were washed with water (50 mL), brine (50 mL), dried (Na₂SO₄), filtered and the solvent was evaporated. The residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether (2:8) to afford the title compound (2.9 g, 91%) as a colorless solid. mp: 75-78° C.

¹H NMR (CDCl₃, 200 MHz): δ 4.37 (s, 4H), 4.62 (s, 2H), 6.96-7.26 (complex, 6H), 7.82 (d, J=8.4 Hz, 2H), 9.89 (s, 1H).

PREPARATION 2 6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]cyanonaphthalene

A mixture of 2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethyl methanesulfonate (0.49 g, 1.82 mmol), 2-hydroxy-6-cyanonaphthalene (0.28, 1.65 mmol) and potassium carbonate (1.15 g, 8.28 mmol) in dry dimethyl formamide (15 mL) was stirred at 80° C. for 12 h. Water (50 mL) was added and extracted with ethyl acetate (2×25 mL). The combined ethyl acetate layer was washed with water (25 mL), brine (20 mL), dried (Na₂SO₄), filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether to afford the title compound (0.41 g, 72%) as a pale yellow solid. mp: 94-96° C.

¹H NMR (CDCl₃, 200 MHz): δ 3.05 (t, J=5.21 Hz, 2H), 3.79-3.85 (complex, 4H), 4.31 (t, J=5.82 Hz, 2H), 6.64-6.78 (complex, 2H), 6.97-7.25 (complex, 4H), 7.53-7.80 (complex, 3H), 8.13 (s, 1H).

PREPARATION 3 6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthaldehyde

To a solution of 6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]cyanonaphthalene (8 g, 22.9 mmol) obtained in preparation 2 in dry tetrahydrofuran (15 mL) was added diisobutyl aluminum hydride (93 mL, 20% in toluene) at −70° C. over a period of 1 h. After the addition reaction mixture was stirred at 25° C. for 16 h. At the end of this time, ethyl formate (20 mL) was added and stirred for 1 h at 25° C. Saturated ammonium chloride solution (15 ML) was added. The reaction mixture was acidified with 10% sulphuric acid and extracted with ethyl acetate (2×75 mL). The combined ethyl acetate layer was washed with water (2×50 mL), brine (50 mL), dried (Na₂SO₄), filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether (10:90) to afford the title compound (4.5 g, 56%) as a pale yellow solid. mp: 100-102° C.

¹H NMR (CDCl₃, 200 MHz): δ 3.06 (t, J=5.2 Hz, 2H), 3.72-3.86 (complex, 4H), 4.33 (t, J=5.67 Hz, 2H), 6.60-6.79 (complex, 2H), 6.97-7.25 (complex, 4H), 7.74-7.93 (complex, 3H), 8.25 (s, 1H), 10.09 (s, 1H).

PREPARATION 4 4-[4-Methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl]methoxybenzaldehyde

To a solution of 4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-methanol (6.0 g, 33.51 mmol) in dichloromethane (20 mL) was added triethylamine (10.15 g, 100.5 mmol) under nitrogen atmosphere at 25° C. Methanesulfonyl chloride (5.75 g, 50.25 mmol) was added to the above reaction mixture at 0° C. and stirring was continued for further 10 h at 25° C. Water (50 mL) was added and extracted with chloroform (2×25 mL). The combined organic extracts were washed with water (50 mL), dried (Na₂SO₄), filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and hexane (2:8) to yield (4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methyl methanesulfonate (3.7 g, 43%) as a syrup.

¹H NMR (CDCl₃, 200 MHz): δ 2.88 (s, 3H), 3.07 (s, 3H), 3.13-3.31 (complex, 2H), 4.41 (d, J=5.2 Hz, 2H), 4.53-4.55 (complex, 1H), 6.81-6.89 (complex, 4H).

A mixture of (4-methyl-3,4-dihydro-2H-1,4-benzoxazin-4-yl)methyl methanesulfonate (3.7 g, 14.39 mmol), 4-hydroxy benzaldehyde (2.6 g, 21.29 mmol) and potassium carbonate (5.9 g, 42.7 mmol) in dry dimethyl formamide (30 mL) was stirred at 80° C. for 10 h. Water (100 mL) was added and extracted with ethyl acetate (2×70 mL). The combined organic layers were washed with water (50 mL), brine (50 mL) and dried (Na₂SO₄), filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether (2:8) to afford the title compound (1.3 g, 32%) as a thick liquid.

¹H NMR (CDCl₃, 200 MHz): δ 2.93 (s, 3H), 3.24-3.46 (complex, 2H), 4.14-4.37 (complex, 2H), 4.68-4.71 (complex, 1H), 6.72-7.10 (complex, 6H), 7.86 (d, J=8.8 Hz, 2H), 9.92 (s, 1H).

PREPARATION 5 4-[4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl]methoxybenzaldehyde

The title compound (3.2 g, 80%) was prepared as a pale yellow solid from 4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-methanol (4.0 g, 15.68 mmol) by a procedure similar to that described for preparation 4. mp: 92-94° C.

¹H NMR (CDCl₃, 200 MHz): δ 3.38-3.43 (complex, 2H), 4.14-4.32 (complex, 2H), 4.46 (d, J=7.8 Hz, 2H), 4.60-4.65 (complex, 1H), 6.65-6.89 (complex, 4H), 7.00 (d, J=8.8 Hz, 2H), 7.32 (s, 5H), 7.83 (d, J=8.8 Hz, 2H), 9.90 (s, 1H).

EXAMPLE 1 Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropenoate

A solution of triethyl 2-ethoxyphosphonoacetate (W. Grell and H. Machleidt, Annalen Chemie, 1960, 699, 53). (7.8 g, 29.1 mmol) in dry tetrahydrofuran (15 mL) was added slowly to a stirred, ice-cooled suspension of sodium hydride (60% dispersion in oil) (1.39 g, 29.1 mmol) in dry tetrahydrofuran (5 mL) under nitrogen atmosphere. The mixture was stirred at 0° C. for 30 minutes followed by the addition of a solution of 4-[2-(2,3-dihydro-1,4-benzoxazin -4-yl)ethoxy]benzaldehyde (7.5 g, 26.5 mmol) which is prepared according to the process described in Preparation 1 disclosed in U.S. patent application Ser. No. 08/982,910, in dry tetrahydrofuran (20 mL). The mixture was allowed to warm to 25° C. and stirred further for 20 h. The solvent was evaporated and the residue was suspended in water (100 mL) and extracted with ethyl acetate (2×75 mL). The combined ethyl acetate layers were washed with water (75 mL), brine (50 mL), dried (Na₂SO₄), filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and petroleum ether (2:8) as eluent to afford the title compound (8.0 g, 75%) a gum as a 65:35 Z:E mixture of geometric isomers (R. A. Aitken and G. L. Thom, Synthesis, 1989,958).

¹H NMR (CDCl₃, 200 MHz) δ: 1.18 and 1.36 (combined 6H, isomeric OEt, triplet signals), 3.51 (t, J=4.48 Hz, 2H), 3.71 (t, J=5.39 Hz, 2H), 3.89-4.03 (complex, 2H), 4.10-4.34 (complex, 6H), 6.07 (s, 0.35H, E olefinic proton), 6.63-7.14 (complex, 6.65H), 7.73 (d, J=8.72 Hz, 2H).

EXAMPLE 2 Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxizin-4yl)ethoxy]phenyl]-2-ethoxypropanoate

A mixture of ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropenoate (8.0 g, 20.0 mmol) obtained in example 1 and magnesium turnings (9.64 g, 396.7 mmol) in dry methanol (50 mL) was stirred at 25° C. for 20 h. At the end of this time water (50 mL) was added and pH was adjusted to ca 7.0 using 10% aqueous hydrochloric acid and the solution was extracted with ethyl acetate (2×10 mL). The combined organic extract was washed with water (75 mL), brine (75 mL), dried (Na₂SO₄), filtered and the solvent was removed under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether (2:8) as an eluent to get the title compound (5.0 g, 64%) as a gummy liquid.

¹H NMR (CDCl₃, 200 MHz) δ: 1.15 (t, J=7.0 Hz, 3H), 2.93 (d, J=6.64 Hz, 2H), 3.23-3.38 (complex, 1H), 3.43-3.72 (complex, 8H), 3.97 (t, J=6.9 Hz, 1H), 4.14 (t, J=5.81 Hz, 2H), 4.19 (t, J=4.2 Hz, 2H), 6.55-6.83 (complex, 6H), 7.13 (d, J=8.39 Hz, 2H).

EXAMPLE 3 Ethyl (E/Z)-3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropenoate

The title compound (0.8 g, 58%) was prepared as a gummy material from 5-formyl-2-(2,3-dihydro-1,4-benzoxazin-4-yl)methyl benzofuran (1.0 g, 3.41 mmol) by a procedure analogous to that described in example 1.

¹H NMR (CDCl₃, 200 MHz) δ: 1.06 and 1.38 (6H, OCH₂CH₃ and OCH₂CH₃, triplet signals), 3.48 (t, J=4.98 Hz, 2H), 3.89-4.18 (complex, 2H), 4.28-4.40 (complex, 4H), 4.54 and 4.56 (combined, 2H, —NCH₂-signals), 6.20 (0.5 H, E isomer of olefinic proton), 6.52 and 6.59 (combined, 1H), 6.65-6.83 (complex, 2.5 H), 7.08-7.11 (complex, 1H), 7.32-7.44 (complex, 2H), 7.69 (d, J=8.3 Hz, 1H), 7.99 (s, 1H).

EXAMPLE 4 Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropenoate

The title compound was prepared as a 38:62 ratio of geometric isomers (as measured by ¹H NMR) (3.2 g, 71%) as a gum, from 4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]benzaldehyde (3.3 g, 11.03 mmol) prepared according to the process described in Preparation 2 disclosed in Patent Application 08/982,910 by a method analogous to that described in example 1.

¹H NMR (CDCl₃, 200 MHz) δ: 1.14 and 1.35 (combined, 6H, isomeric —OCH₂CH₃ triplet signals), 3.02 (t, J=4.9 Hz, 2H), 3.69-3.88 (complex, 4H), 3.92-4.03 (complex, 2H), 4.12-4.33 (complex, 4H), 6.06 (s, 0.38 H, E olefinic proton), 6.61-7.14 (complex, 6.62 H), 7.73 (d, J=8.81 Hz, 2H).

EXAMPLE 5 Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoate

The title compound (0.6 g, 78%) was prepared as a gum from Ethyl (E/Z)-3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropenoate (0.8 g, 1.96 mmol) obtained in example 3 by a procedure analogous to that described for example 2.

¹H NMR (CDCl₃, 200 MHz) δ: 1.15 (t, J=7.0 Hz, 3H), 3.07 (d,J=5.8 Hz, 2H), 3.28-3.67 (complex, 4H), 3.70 (s, 3H), 4.03 (t, J=6.0 Hz, 1H), 4.28 (t, J=4.47 Hz, 2H), 4.54 (s, 2H), 6.52 (s, 1H), 6.62-6.89 (complex, 4H), 7.10 (d, J=7.05 Hz, 1H), 7.35 (complex, 2H).

EXAMPLE 6 Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate

The title compound (2.3 g, 76%) was prepared as a gummy liquid from ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropenoate (3.1 g, 7.50 mmol) obtained in example 4 by an analogous procedure to that described in example 2.

¹H NMR (CDCl₃, 200 MHz) δ: 1.15 (t, J=7.01 Hz, 3H), 2.93 (d, J=6.65 Hz, 2H), 3.03 (t, J=5.21 Hz, 2H), 3.23-3.41 (complex, 1H), 3.52-3.80 (complex, 8H), 3.97 (t, J=7.01 Hz, 1H), 4.14 (t, J=5.81 Hz, 2H), 6.61-6.82 (complex, 4H), 6.92-7.05 (complex, 2H), 7.13 (d, J=8.53 Hz, 2H).

EXAMPLE 7 Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate

To a solution of methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate (0.6 g, 1.5 mmol) obtained in example 2 in dry tetrahydrofuran (5 mL) was added lithium diisopropyl amide (5.25 μL, 0.5 mL solution in THF/hexane) at −78° C. After stirring for 1 h at −78° C., methyl iodide (0.75 mL) was added and the reaction mixture was allowed to warm to room temperature (ca 25° C.) and stirred for further 20 h at the same temperature. Water (20 mL) was added, acidified with 1 N hydrochloric acid and extracted with ethyl acetate (2×25 mL). The combined ethyl acetate layer was washed with water (25 mL), brine (25 mL), dried (Na₂SO₄), filtered and the solvent was evaporated under reduced pressure to afford the title compound (0.5 g, 80%) as an oil.

¹H NMR (CDCl₃, 200 MHz): δ 1.21 (t, J=6.97 Hz, 3H), 1.31 (s, 3H), 2.95 (s, 2H), 3.32-3.58 (complex, 4H), 3.62-3.84 (complex, 5H), 4.14 (t, J=5.81 Hz, 2H), 4.22 (t, J=4.25 Hz, 2H), 6.55-6.88 (complex, 6H), 7.08 (d, J=8.63 Hz, 2H).

EXAMPLE 8 Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3 dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate

The title compound (0.6 g, 78%) was prepared as a brown liquid from methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate (0.6 g, 1.5 mmol) obtained in example 2 by an analogous procedure to that described in example 7.

¹H NMR (CDCl₃, 200 MHz) δ: 1.22 (t, J=6.96 Hz, 3H), 3.03-3.18 (complex, 4H), 3.51 (t, J=4.2 Hz, 2H), 3.59-3.71 (complex, 7H), 4.14 (t, J=5.81 Hz, 2H), 4.22 (t, J=4.24 Hz, 2H), 6.42-6.85 (complex, 6H), 6.90-7.32 (complex 6H).

EXAMPLE 9 Ethyl (E/Z)-3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropenoate

The title compound (3.9 g, 97%) was obtained in 32:68 ratio of E:Z isomers as a white solid from 4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]benzaldehyde (2.9 g, 9.7 mmol) obtained in preparation 1 by an analogous procedure to that described in example 1. mp: 92-95° C.

¹H NMR (CDCl₃, 200 MHz) δ: 1.13-1.43 (complex, 6H), 3.88-4.02 (complex, 2H), 4.07-4.40 (complex, 6H), 4.60 (s, 2H), 6.05 (s, 0.32 H, E olefinic proton), 6.76-7.32 (complex, 6.68 H), 7.71 (d, J=8.72 Hz, 2H).

EXAMPLE 10 Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4yl)ethoxy]phenyl]-2-ethoxypropanoate

The title compound (1.0 g, 51%) was prepared as a colorless syrup from ethyl (E/Z)-3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropenoate (2.0 g, 4.8 mmol) obtained in example 9 by a procedure analogous to that described in example 2.

¹H NMR (CDCl₃, 200 MHz): δ 1.14 (t, J=7.0 Hz, 3H), 2.92 (d, J=6.6 Hz, 2H), 3.25-3.41 (complex, 1H), 3.53-3.61 (complex, 1H), 3.68 (s, 3H), 3.96 (t, J=7.0 Hz, 1H), 4.21-4.32 (complex, 4H), 4.68 (s, 2H), 6.77 (d, J=8.63 Hz, 2H), 6.98-7.33 (complex, 6H).

EXAMPLE 11 Ethyl (E/Z)-3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropenoate

The title compound as a 1:1 mixture of E/Z isomers (1.74 g, 87%) was prepared as a brown syrup from 6-[2-(2,3dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthaldehyde (1.5 g, 4.29 mmol) obtained in preparation 3 by a procedure analogous to that described in example 1.

¹H NMR (CDCl₃, 200 MHz): δ 0.99-1.47 (complex, 6H), 3.06 (t, J=4.98 Hz, 2H), 3.79-3.95 (complex, 4H), 3.99-4.18 (complex, 2H), 4.25-4.37 (complex, 4H), 6.23 (s, 0.5 H, E olefinic proton), 6.59-6.79 (complex, 2H), 6.97-7.29 (complex, 4.5H), 7.57-7.95 (complex, 3H), 8.14 (s, 1H).

EXAMPLE 12 Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoate

The title compound (1.25 g, 75%) was prepared as a colorless syrup from ethyl (E/Z)-3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropenoate (1.7 g, 3.67 mmol) obtained in example 11 by an analogous procedure to that described in example 2.

¹H NMR (CDCl₃, 200 MHz): δ 1.14 (t, J=7.06 Hz, 3H), 3.06 (t, J=5.21 Hz, 2H), 3.13 (d, J=7.15 Hz, 2H), 3.29-3.37 (complex, 1H), 3.57-3.64 (complex, 1H), 3.70 (s, 3H), 3.77-3.83 (complex, 4H), 4.09 (t, J=7.2 Hz, 1H), 4.25 (t, J=5.81 Hz, 2H), 6.62-6.79 (complex, 2H), 6.96-7.36 (complex, 5H), 7.60-7.70 (complex, 3H).

EXAMPLE 13 Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate

The title compound (0.14 g, 32%) was prepared as a gummy liquid from 2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethyl methanesulfonate (0.36 g, 1.42 mmol), potassium carbonate (0.80 g, 5.8 mmol) and ethyl 2-hydroxy-3-(4-hydroxyphenyl)propanoate (0.3 g, 1.42 mmol) using conditions analogous to that described in preparation 2.

¹H NMR (CDCl₃, 200 MHz): δ 1.24 (t, J=7.15 Hz, 3H), 2.71 (d, J=6.23 Hz, 1H, D₂O exchangeable), 2.84-3.10 (complex, 2H), 3.50 (t, J=4.47 Hz, 2H), 3.67 (t, J=5.48 Hz, 2H), 4.11-4.26 (complex, 6H), 4.37-4.39 (complex, 1H), 6.61-6.86 (complex, 6H), 7.11 (d, J=8.62 Hz, 2H).

EXAMPLE 14 Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate

The title compound (1.9 g, 17%) was prepared as a gummy liquid from 2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethyl methanesulfonate (8.2 g, 30.0 mmol), potassium carbonate (20.7 g, 150 mmol) and ethyl 2-hydroxy-3-(4-hydroxyphenyl)propanoate (6.3 g, 30.0 mmol) using conditions analogous to that described in preparation 2.

¹H NMR (CDCl₃, 200 MHz): δ 1.29 (t, J=7.11 Hz, 3H), 2.70-2.80 (bs, 1H, D₂O exchangeable), 2.82-3.15 (complex, 4H), 3.65-3.82 (complex, 4H), 4.10-4.30 (complex, 4H), 4.28-4.40 (complex, 1H), 6.62-6.89 (complex, 4H), 6.92-7.18 (complex, 4H).

EXAMPLE 15 Ethyl 3-[4-[2-(2,3dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoate

A solution of ethyl 3-[4-[2-(2,3dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate (0.5 g, 1.34 mmol) obtained in example 13 in dry dimethyl formamide (5 mL) was added to a stirred ice cooled suspension of sodium hydride (60% dispension in oil) (0.08 g, 1.66 mmol) in dry dimethyl formamide (3 mL) under nitrogen atmosphere. The reaction mixture was stirred at 0° C. for 30 minutes followed by the addition of benzyl bromide (0.46 g, 2.69 mmol). The mixture was allowed to warm to 25° C. and stirring was continued for further 18 h. Water (25 mL) was added and extracted with ethyl acetate (2×50 mL). The combined organic layer was washed with water (50 mL), brine (50 mL) and dried Na₂SO₄ and filtered. The solvent was evaporated under reduced pressure and the residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether (2:8) as eluent to afford the title compound (0.3 g) along with benzyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoate. This mixture (1:1) is used in example 47 without any separation.

¹H NMR (CDCl₃, 200 MHz): δ 1.23 (t, J=7.05 Hz, 1.5H), 2.99 (d, J=7.06 Hz, 4H), 3.0-3.72 (complex, 8H), 4.05-4.30 (complex, 12H), 4.32-4.71 (complex, 4H), 5.13 (s, 2H), 6.55-6.89 (complex, 12H), 7.05-7.36 (complex, 19H).

EXAMPLE 16 Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoate

The title compound (0.4 g, 52%) was prepared as a gummy liquid from 2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethyl methanesulfonate (0.46 g, 1.78 mmol), potassium carbonate (0.98 g, 7.12 mmol) and ethyl 2-butoxy-3-(4-hydroxyphenyl)propanoate (0.47 g, 1.78 mmol) using conditions analogous to that described in preparation 2.

¹H NMR (CDCl₃, 200 MHz): δ 0.84 (t, J=7.53 Hz, 3H), 1.19-1.34 (complex, 5H), 1.43-1.55 (complex, 2H), 2.92 (d, J=6.32 Hz, 2H), 3.22-3.36 (complex, 1H), 3.48-3.59 (complex, 3H), 3.68 (t, J=5.82 Hz, 2H), 3.93 (t, J=6.2 Hz, 1H), 4.11-4.24 (complex, 6H), 6.61-6.86 (complex, 6H), 7.13 (d, J=8.3 Hz, 2H).

EXAMPLE 17 Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoate

The title compound (0.31 g, 50%) was prepared as a colorless syrup from 2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethyl methanesulfonate (0.35 g, 1.3 mmol), potassium carbonate (0.75 g, 5.4 mmol) and ethyl 2-hexyloxy-3-(4-hydroxyphenyl) propanoate (0.4 g, 1.3 mmol) using conditions analogous to that described in preparation 2.

¹H NMR (CDCl₃, 200 MHz): δ 0.85 (t, J=5.72 Hz, 3H), 1.20-1.34 (complex, 7H), 1.40-1.66 (complex, 4H), 2.93 (d, J=6.0 Hz, 2H), 3.21-3.31 (complex, 1H), 3.49-3.60 (complex, 3H), 3.68 (t, J=5.72 Hz, 2H), 3.93 (t, J=5.81 Hz, 1H), 4.11-4.24 (complex, 6H), 6.62-6.81 (complex, 5H), 7.09-7.16 (complex, 3H).

EXAMPLE 18 Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropenoate

The title compound (0.92 g, 58%) was prepared as a mixture of E:Z isomers (40:60) as a syrupy liquid from 4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]benzaldehyde (1.0 g, 3.0 mmol) and triethyl 2-phenoxyphosphonoacetate (A. G. Schultz, et. al. J Org Chem., 1983, 48, 3408) (1.3 g, 4.0 mmol) by an analogous procedure to that described in example 1.

¹H NMR (CDCl₃, 200 MHz): δ 1.06 and 1.18 (combined 3H, isomeric OCH₂CH₃, triplet signals), 3.43-3.57 (complex, 2H), 3.64-3.75 (complex, 2H), 4.06-4.28 (complex, 6H), 6.60-6.90 (complex, 8H), 6.94-7.12 (complex, 2H), 7.22-7.45 (complex, 3H), 7.64 (d, J=8.72 Hz, 1H).

EXAMPLE 19 Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate

The title compound (0.49 g, 57%) was prepared as a gummy material from ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropenoate (0.9 g, 2.0 mmol) obtained in example 18 by an analogous procedure to that described for example 2.

¹H NMR (CDCl₃, 200 MHz): δ 3.17 (d, J=6.2 Hz, 2H), 3.50 (t, J=4.3 Hz, 2H), 3.65-3.70 (complex, 5H), 4.14 (t, J=5.76 Hz, 2H), 4.21 (t, J=4.15 Hz, 2H), 4.75 (t, J=6.4 Hz, 1H), 6.61-6.98 (complex, 9H), 7.17-7.27 (complex, 4H).

EXAMPLE 20 Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropenoate

The title compound (3.7 g, 60%) was prepared as a mixture of E:Z isomers (35:65) as a gummy material from 4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]benzaldehyde (4.0 g, 13.0 mmol) and triethyl 2-phenoxyphosphonoacetate (A. G. Schultz, et. al. J Org. Chem. 1983, 48, 3408), (5.07 g, 16.0 mmol) by an analogous procedure to that described in example 1.

¹H NMR (CDCl₃, 200 MHz): δ 1.05-1.36 (complex, 3H), 3.00-3.11 (complex, 2H), 3.64-3.85 (complex, 4H), 4.09-4.30 (complex, 4H), 6.58-7.13 (complex, 8H), 7.20-7.46 (complex, 4H), 7.65 (d, J=8.7 Hz, 2H).

EXAMPLE 21 Methyl 3-[4-[12-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate

The title compound (2.3 g, 64%) was prepared as a gummy material from ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropenoate (3.7 g, 8.0 mmol) obtained in example 20 by an analogous procedure to that described for example 2.

¹H NMR (CDCl₃, 200 MHz): δ 2.99 (t, J=5.439 Hz, 2H), 3.15 (d, J=5.99 Hz, 2H), 3.60-3.78 (complex, 7H), 4.13 (t, J=5.4 Hz, 2H), 4.74 (t, J=6.23 Hz, 1H), 6.58-6.89 (complex, 6H), 6.90-7.06 (complex, 2H), 7.11-7.30 (complex, 5H).

EXAMPLE 22 Ethyl (E/Z)-3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropenoate

The title compound (0.4 g, 25%) was prepared as a mixture of E:Z isomers (1:1) as a brown liquid from 4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxybenzaldehyde (1.2 g, 4.24 mmol) obtained in preparation 4 by an analogous procedure to that described in example 1.

¹H NMR (CDCl₃, 200 MHz): δ 1.36 (t, J=7.1 Hz, 6H), 2.90 (s, 3H), 3.26-3.45 (complex, 2H), 3.99 (q, J=7.2 Hz, 2H), 4.10-4.38 (complex, 4H), 4.50-4.60 (complex, 1H), 6.70 (d, J=7.47 Hz, 2H), 6.81-6.90 (complex, 5H), 7.75(d, J=8.8 Hz, 2H).

EXAMPLE 23 Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate

The title compound (0.25 g, 65%) was prepared as a thick liquid from ethyl (E/Z)-3-[4-(4-methyl-3,4-dihydro-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropenoate (0.4 g, 1.0 mmol) obtained in example 22 by an analogous procedure to that described in example 2.

¹H NMR (CDCl₃, 200 MHz): δ 1.16 (t, J=7.0 Hz, 3H), 2.89 (s, 3H), 2.95 (d, J=6.2 Hz, 2H), 3.19-3.41 (complex, 3H), 3.55-3.66 (complex, 1H), 3.70 (s, 3H), 3.95-4.24 (complex, 3H), 4.60-4.64 (complex, 1H), 6.64-7.08 (complex, 6H), 7.15 (d, J=8.4 Hz, 2H).

EXAMPLE 24 Ethyl (E/Z-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropenoate

The title compound (3.0 g, 76%) was prepared as E:Z isomers (1:1), as a syrupy liquid from 4-[4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxybenzaldehyde (3.0 g, 8.35 mmol) obtained in preparation 5 by a procedure analogous to that described for example 1.

¹H NMR (CDCl₃, 200 MHz): δ 1.33-1.40 (complex, 6H), 3.39-3.44 (complex, 2H), 3.99 (q, J=7.0 Hz, 2H), 4.11-4.38 (complex, 4H), 4.46 (d, J=5.0 Hz, 2H), 4.52-4.66 (complex, 1H), 6.60-6.97 (complex, 7H), 7.28 (s, 5H), 7.75 (d, J=8.8 Hz, 2H).

EXAMPLE 25 Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate

The title compound (1.5 g, 100%) was prepared from ethyl (E/Z)-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropenoate (1.5 g, 3.17 mmol) obtained in example 24 by an analogous procedure to that described in example 2.

¹H NMR (CDCl₃, 200 MHz): δ 1.17 (t, J=7.0 Hz, 3H), 2.96 (d, J=6.6 Hz, 2H), 3.31-3.57 (complex, 3H), 3.60-3.70 (complex, 1H), 3.71 (s, 3H), 3.97-4.26 (complex, 3H), 4.47 (d, J=4.0 Hz, 2H), 4.56-4.61 (complex, 1H), 6.68-6.90 (complex, 6H), 7.15 (d, J=8.5 Hz, 2H), 7.29 (s, 5H).

EXAMPLE 26 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid

To a solution of methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate (4.7 g, 12.2 mmol) obtained in example 2 in methanol (50 mL) was added aqueous 10% sodium hydroxide (28 mL). The mixture was stirred at 25° C. for 3h. The solvent was removed under reduced pressure and the residue was acidified with 2N hydrochloric acid extracted with ethyl acetate (2×100 mL). The combined ethyl acetate layers were washed with water (75 mL), brine (50 mL), dried (Na₂SO₄), filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using ethyl acetate to give the title compound (3.0 g, 66%) as a syrupy liquid.

¹H NMR (CDCl₃, 200 MHz): δ 1.17 (t, J=6.96 Hz, 3H), 2.85-3.12 (complex, 2H), 3.40-3.61 (complex, 4H), 3.69 (t, J=5.72 Hz, 2H), 4.04 (dd, J=7.38 and 4.27 Hz, 1H), 4.10-4.28 (complex, 4H), 6.52-6.85 (complex, 6H), 7.14 (d, J=8.6 Hz, 2H), COOH proton is too broad to observe.

EXAMPLE 27 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid, sodium salt

A mixture of 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.15 g, 0.4 mmol) obtained in example 26 and sodium methoxide (23.4 mg) in methanol (5 mL) was stirred at 25° C. for 2h. The solvent was removed and the residue was triturated with dry ether (3×10 mL). The precipitated solids were filtered, washed with dry ether (2×5 mL) and dried over P₂O₅ under vacuum to afford the title compound (0.12 g, 75%) as a colorless hygroscopic solid.

¹H NMR (DMSO-d₆, 200 MHz): δ 0.98 (t, J=6.83 Hz, 3H), 2.60-2.69 (complex, 1H), 2.78-2.92 (complex, 1H), 3.05-3.21 (complex, 2H), 3.41-3.75 (complex, 5H), 4.08-4.21 (complex, 4H), 6.49-6.85 (complex, 6H), 7.12 (d, J=8.3 Hz, 2H).

EXAMPLE 28 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid

The title compound (0.5 g, 87%) was prepared as a gummy material from methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methyl benzofuran-5-yl]-2-ethoxypropanoate (0.6 g, 1.51 mmol) obtained in example 5 by a procedure analogous to that described for example 26.

¹H NMR (CDCl₃, 200 MHz) δ: 1.26 (t, J=7.06 Hz, 3H), 3.05-3.28 (complex, 2H), 3.40-3.68 (complex, 4H), 4.09 (dd, J=7.47 and 4.24 Hz, 1H), 4.28 (t, J=4.15 Hz, 2H), 4.53 (s, 2H), 6.52 (s, 1H), 6.60-6.90 (complex, 4H), 7.13 (d, J=8.7 Hz, 1H), 7.32-7.36 (complex, 2H), COOH proton is too broad to observe.

EXAMPLE 29 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid

The title compound (1.4 g, 63%) was prepared as a gummy material from methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate (2.3 g, 5.73 mmol) obtained in example 6 by a procedure analogous to that described for example 26.

¹H NMR (CDCl₃, 200 MHz) δ: 1.18 (t, J=7.0 Hz, 3H), 2.82-3.15 (complex, 4H), 3.40-3.68 (complex, 2H), 3.70-3.81 (complex, 4H), 4.05 (dd, J=7.29, 4.33 Hz, 1H), 4.16 (t, J=5.72 Hz, 2H), 6.68-6.74 (complex, 2H), 6.81 (d, J=8.5 Hz, 2H), 6.94-7.06 (complex, 2H), 7.14 (d, J=8.5 Hz, 2H). COOH proton is too broad to observe.

EXAMPLE 30 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid, sodium salt

The title compound (0.42 g, 81%) was prepared as a colorless solid from 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.5 g, 1.30 mmol) obtained in example 29 by an analogous procedure to that described for example 27.

¹H NMR (CDCl₃, 200 MHz): δ 0.98 (t, J=7.0 Hz, 3H), 2.72-3.25 (complex, 5H), 3.30-3.51 (complex, 1H), 3.61-3.73 (complex, 4H), 3.82-3.91 (complex, 1H), 4.04 (t, J=5.72 Hz, 2H), 6.52-6.79 (complex, 4H), 6.91-7.03 (complex, 2H), 7.10 (d, J=8.4 Hz, 2H).

EXAMPLE 31 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide

A solution of oxalyl chloride (0.28 mL, 3.1 mmol) and 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.6 g, 1.55 mmol) obtained in example 29 in dry dichloromethane (10 mL) was refluxed for 2 h. The solvent and excess oxalyl chloride were removed under reduced pressure. The residue was dissolved in dichloromethane and stirred with aqueous ammonia (5 mL) for 30 min. The reaction mixture was extracted with chloroform (2×25 mL). The combined chloroform layer was washed with water (25 mL), dried (Na₂SO₄), filtered, and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether (7:3) as an eluent to afford the title compound (0.32 g, 54%) as a white solid. mp: 120-122° C.

¹H NMR (CDCl₃, 200 MHz): δ 1.15 (t, J=6.96 Hz, 3H), 2.81-3.20 (complex, 4H), 3.38-3.58 (complex, 2H), 3.71-3.90 (complex, 4H), 3.91 (dd, J=7.38 and 3.73 Hz, 1H), 4.16 (t, J=5.58 Hz, 2H), 5.54 (bs, D₂O exchangeable, 1H), 6.44 (bs, D₂O exchangeable, 1H), 6.59-6.84 (complex, 4H), 6.92-7.19 (complex, 4H).

EXAMPLE 32 N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide

To an ice cooled solution of 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.3 g, 0.78 mmol) obtained in example 29 and triethylamine (0.162 g, 1.6 mmol) in dry chloromethane (10 mL) was added pivaloyl chloride (0.10 g, 0.86 mmol) and stirring was continued for 30 min at 0° C. To the above reaction mixture, methyl amine (40% solution) (0.124 mL) was added at 25° C. and stirring was continued for 1 h at 25° C. Water (20 mL) was added and extracted with ethyl acetate (2×20 mL). The combined organic extract was washed with water (10 mL), brine (10 mL), dried (Na₂SO₄), filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether (1:1) to afford the title compound as a colorless solid. mp: 80-82° C.

¹H NMR (CDCl₃, 200 MHz): δ 1.11 (t, J=7.0 Hz, 3H), 2.76 (d, J=4.89 Hz, 3H), 2.81-2.88 (complex, 1H), 3.01-3.12 (complex, 3H), 3.39-3.52 (complex, 2H), 3.70-3.81 (complex, 4H), 3.86-3.91 (complex, 1H), 4.14 (t, J=5.81 Hz, 2H), 6.48 (bs, 1H), 6.61-6.81 (complex, 4H), 6.94-7.14 (complex, 4H).

EXAMPLE 33 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide

The title compound (0.2 g, 80%) was prepared as a white solid from 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2ethoxypropanoic acid (0.25 g, 0.67 mmol) obtained in example 26 and aqueous ammonia (4 mL) by an analogous procedure to that described in example 31. mp: 107-109° C.

¹H NMR (CDCl₃, 200 MHz): δ 1.13 (t, J=6.96 Hz 3H), 2.81-2.93 (complex, 1H), 3.03-3.19 (complex, 1H), 3.34-3.59 (complex, 4H), 3.69 (t, J=5.53 Hz, 2H), 3.88 (dd, J=7.43 and 3.7 Hz, 1H), 4.15 (t, J=5.58 Hz, 2H), 4.28 (t, J=4.24 Hz, 2H), 5.49 (bs, 1H, D₂O exchangeable), 6.43 (bs, 1H, D₂O exchangeable), 6.68-6.87 (complex, 6H), 7.15 (d, J=8.49 Hz, 2H).

EXAMPLE 34 N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide

The title compound (0.23 g, 74%) was prepared as a white solid from 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.3 g, 0.8 mmol) obtained in example 26 and methylamine (40% solution) (2 mL) by an analogous procedure to that described in example 32. mp: 97-99° C.

¹H NMR (CDCl₃, 200 MHz): δ 1.14 (t, J=7.0 Hz, 3H), 2.76 (d, J=4.98 Hz, 3H), 4.80-4.90 (complex, 1H), 3.02-3.14 (complex, 1H), 3.35-3.45 (complex, 2H), 3.52 (t, J=4.57 Hz, 2H), 3.68 (t, J=5.81 Hz, 2H), 7.88 (dd, J=7.06 and 3.74 Hz, 1H), 4.14 (t, J=5.72 Hz, 2H), 4.22 (t, J=4.15 Hz, 2H), 6.50 (bs, 1H), 6.55-6.89 (complex, 6H), 7.11 (d, J=8.3 Hz, 2H).

EXAMPLE 35 N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide

The title compound (0.25 g, 67%) was prepared as a white solid from 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.3 g, 0.8 mmol) obtained in example 26 and benzyl amine (0.095 g, 0.88 mmol) by a procedure analogous to that described in example 32. mp: 94-96° C.

¹H NMR (CDCl₃, 200 MHz): δ 1.11 (t, J=7.0 Hz, 3H), 2.82-3.18 (complex, 2H), 3.40-3.55 (complex, 4H), 3.70 (t, J=5.49 Hz, 2H), 3.94-3.98 (complex, 1H), 4.14 (t, J=5.72 Hz, 2H), 4.23 (t, J=4.24 Hz, 2H), 4.28-4.52 (complex, 2H), 6.60-6.87 (complex, 6H), 7.06-7.32 (complex, 7H). CONH proton is too broad to observe.

EXAMPLE 36 N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide

The title compound (0.22 g, 74%) was prepared as a white solid from 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.25 g, 0.65 mmol) obtained in example 29 and benzylamine (0.076 g, 0.71 mmol) by an analogous procedure to that described in example 32. mp: 92-93° C.

¹H NMR (CDCl₃, 200 MHz): δ 1.15 (t, J=7.0 Hz, 3H), 2.88-3.20 (complex, 4H), 3.42-3.60 (complex, 2H), 3.73-3.87 (complex, 4H), 3.98-4.06 (complex, 1H), 4.18 (t, J=5.72 Hz, 2H), 4.30-4.56 (complex, 2H), 6.61-6.90 (complex, 4H), 7.00-7.43 (complex, 9H), CONH proton is too broad to observe.

EXAMPLE 37 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid

The title compound (0.3 g, 62%) was prepared as a gummy liquid from methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate (0.5 g, 1.2 mmol) obtained in example 7 by an analogous procedure to that described in example 26.

¹H NMR (CDCl₃, 200 MHz) δ: 1.24 (complex, 6H), 2.98, 3.04 (1H each, 2d, J=14.1 Hz each), 3.51 (t, J=4.25 Hz, 2H), 3.49-3.71 (complex, 4H), 4.15 (t, J=5.63 Hz, 2H), 4.22 (t, J=4.48 Hz, 2H), 6.60-6.87 (complex, 6H), 7.07 (d, J=8.67 Hz, 2H), COOH proton is too broad to observe.

EXAMPLE 38 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid, sodium salt

The title compound (0.12 g, 51%) was prepared as a white solid from 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.22 g, 0.57 mmol) obtained in example 37 by an analogous procedure to that described in example 27.

¹H NMR (DMSO-d₆, 200 MHz) δ: 0.96-1.08 (complex, 6H), 2.79 (s, 2H), 3.28-3.52 (complex, 4H), 3.64 (t, J=5.3 Hz, 2H), 4.05-4.19 (complex, 4H), 6.48-6.59 (complex, 1H), 6.62-6.86 (complex, 4H), 7.03-7.28 (complex, 3H).

EXAMPLE 39 2-(2-Fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid

The title compound (0.25 g, 42%) was prepared as a gummy liquid from methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate (0.6 g, 1.2 mmol) obtained in example 8 by an analogous procedure to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 1.12 (t, J=6.82 Hz, 3H), 1.65 (bs, 1H, D₂O exchangeable), 3.11-3.42 (complex, 4H), 3.50 (t, J=4.34 Hz, 2H), 3.68 (t, J=5.67 Hz, 2H), 3.70-3.89 (complex, 2H), 4.14 (t, J=5.67 Hz, 2H), 4.21 (t, J=4.15 Hz, 2H), 6.62-6.86 (complex, 6H), 7.03-7.12 (complex, 4H), 7.18-7.30 (complex, 2H).

EXAMPLE 40 2-(2-Fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid, sodium salt

The title compound (0.11 g, 48%) was prepared as a white solid from 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.22 g, 0.45 mmol) obtained in example 39 by an analogous procedure to that described in example 27.

¹H NMR (CDCl₃, 200 MHz): δ 1.02 (t, J=6.65 Hz, 3H), 2.75-2.92 (complex, 4H), 3.39-3.58 (complex, 4H), 3.62 (bs, 2H), 4.04-4.20 (complex, 4H), 6.49-6.82 (complex, 5H), 6.90-7.28 (complex, 6H), 7.49-7.13 (complex, 1H).

EXAMPLE 41 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid

The title compound (0.75 g, 77%) was prepared as a white solid from methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate (1.0 g, 2.5 mmol) obtained in example 10 by a procedure analogous to that described in example 26. mp: 90-03° C.

¹H NM (CDCl₃, 200 MHz): δ 1.18 (t, J=6.96 Hz, 3H), 2.88-3.13 (complex, 2H), 3.41-3.63 (complex, 2H), 4.06 (dd, J=7.43 and 4.33 Hz, 1H), 4.25-4.52 (complex, 4H), 4.61 (s, 2H), 6.80 (d, J=8.62 Hz, 2H), 7.00-7.34 (complex, 6H). COOH proton is too broad to observe.

EXAMPLE 42 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid, sodium salt

The title compound (0.12 g, 56%) was prepared as a white solid from 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.2 g, 0.51 mmol) obtained in example 41 by an analogous procedure to that described in example 27.

¹H NMR (CDCl₃, 200 MHz): δ 0.99 (t, J=6.97 Hz, 3H), 2.61-2.80 (complex, 2H), 3.32-3.57 (complex, 1H), 3.60-3.72 (complex, 1H), 3.65-3.70 (complex, 1H), 4.18 (bs, 2H), 4.30 (bs, 2H), 4.68 (s, 2H), 6.78 (d, J=8.4 Hz, 2H), 7.03-7.14 (complex, 5H), 7.42 (d, J=7.06 Hz, 1H).

EXAMPLE 43 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid

The title compound (0.8 g, 69%) was prepared as a white solid from methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoate (1.2 g, 2.66 mmol) obtained in example 12 by an analogous procedure to that described in example 26. mp: 102-104° C.

¹H NMR (CDCl₃, 200 MHz): δ 1.15 (t, J=7.01 Hz, 3H), 3.06 (t, J=4.98 Hz, 2H), 3.08-3.63 (complex, 4H), 3.77-3.83 (complex, 4H), 4.15 (dd, J=4.15 and 4.18 Hz, 1H), 4.28 (t, J=5.95 Hz, 2H), 6.59-6.79 (complex, 2H), 6.96-7.36 (complex, 5H), 7.61-7.79 (complex, 3H). COOH proton is too broad to observe.

EXAMPLE 44 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid, sodium salt

The title compound (0.16 g, 76%) was prepared as a white solid from 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid (0.2 g, 0.457 mmol) obtained in example 43 by an analogous procedure to that described in example 27. mp: 138-140° C.

¹H NMR (DMSO-d₆, 200 MHz): δ 0.98 (t, J=7.06 Hz, 3H), 2.72-2.90 (complex, 1H), 2.92-3.21 (complex, 3H), 3.32-3.54 (complex, 2H), 3.61-3.91 (complex, 5H), 4.28 (bs, 2H), 6.56 (t, J=7.00 Hz, 1H), 6.73-7.00 (complex, 3H), 7.05-7.30 (complex, 2H), 7.38 (d, J=8.3 Hz, 1H), 7.60-7.82 (complex, 3H).

EXAMPLE 45 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid

The title compound (0.06 g, 43%) was prepared as a brown syrupy liquid from ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate (0.15 g, 0.40 mmol) obtained in example 13 by an analogous procedure to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 2.85-3.19 (complex, 2H), 3.43 (t, J=4.15 Hz, 2H), 3.61 (t, J=5.49 Hz, 2H), 4.07 (t, J=5.40 Hz, 2H), 4.16 (t, J=4.48 Hz, 2H), 4.45 (bs, 1H), 6.50-6.82 (complex, 6H), 7.08 (d, J=7.88 Hz, 2H). COOH and OH protons are too broad to observe.

EXAMPLE 46 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid

The title compound (0.7 g, 46%) was prepared as a white solid from ethyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate (1.7 g, 4.39 mmol) obtained in example 14 by a procedure analogous to that described in example 26. mp: 74-76° C.

¹H NMR (CDCl₃, 200 MHz): δ 2.88-3.18 (complex, 4H), 3.69-3.79 (complex, 4H), 4.15 (t, J=5.72 Hz, 2H), 4.45 (dd, J=6.73 and 4.79 Hz, 1H), 4.51-4.97 (bs, D₂O exchangeable, 1H), 6.65-6.89 (complex, 4H), 6.94-7.17 (complex, 4H), COOH proton is too broad to observe.

EXAMPLE 47 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoic acid

The title compound (0.15 g, 67%) was prepared as a thick liquid from ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoate (0.24 g, 0.52 mmol) obtained in example 15 by a procedure analogous to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 1.40-2.80 (br, 1H, D₂O exchangeable), 2.99-3.18 (complex, 2H), 3.51 (t, J=4.34 Hz, 2H), 3.70 (t, J=5.82 Hz, 2H), 4.13-4.24 (complex, 5H), 4.51 (d, J=17.0 Hz, 2H), 6.60-6.89 (complex, 6H), 7.10-7.37 (complex, 7H).

EXAMPLE 48 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoic acid, sodium salt

The title compound (0.1 g, 73%) was prepared as a cream colored hygroscopic solid from 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoic acid (0.13 g, 0.30 mmol) obtained in example 47 by a procedure analogous to that described in example 27.

¹H NMR (DMSO-d₆, 200 MHz): δ 2.62-2.74 (complex, 1H), 2.89-2.98 (complex, 1H), 3.48 (t, J=4.2 Hz, 2H), 3.67 (t, J=5.48 Hz, 2H), 4.12-4.26 (complex, 5H), 4.65 (d, J=12.45 Hz, 2H), 6.45-6.84 (complex, 6H), 7.12-7.25 (complex, 7H).

EXAMPLE 49 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid

The title compound (0.25 g, 67%) was prepared as a syrupy liquid from ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoate (0.4 g, 0.93 mmol), obtained in example 16 by an analogous procedure to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 0.87 (t, J=7.15 Hz, 3H), 1.25-1.40 (complex, 2H), 1.49-1.66 (complex, 2H), 2.95-3.15 (complex, 2H), 3.43-3.53 (complex, 4H), 3.68 (t, J=5.49 Hz, 2H), 4.00-4.12 (complex, 1H), 4.14 (t, J=5.65 Hz, 2H), 4.22 (t, J=4.25 Hz, 2H), 6.60-6.89 (complex, 6H), 7.12 (d, J=8.39 Hz, 2H). COOH proton is too broad to observe.

EXAMPLE 50 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid, sodium salt

The title compound (0.12 g, 57%) was prepared as a hygroscopic cream colored solid from 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid (0.2 g, 0.5 mmol) obtained in example 49 by an analogous procedure to that described in example 27.

¹H NMR (DMSO-d₆, 200 MHz): δ 0.78 (t, J=7.06 Hz, 3H), 1.16-1.56 (complex, 4H), 2.52-2.64 (complex, 1H), 2.79-2.87 (complex, 1H), 2.99-3.18 (complex, 2H), 3.40 (bs, 2H), 3.66 (t, J=5.31 Hz, 2H), 4.10-4.25 (complex, 5H), 6.52-6.90 (complex, 6H), 7.12 (d, J=8.3 Hz, 2H).

EXAMPLE 51 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoic acid

The title compound (0.17 g, 60%) was prepared as a greenish liquid from ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoate (0.3 g, 0.65 mmol) obtained in example 17 by a procedure analogous to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 0.86 (t, J=5.72 Hz, 3H), 1.25-1.33 (complex, 4H), 1.41-1.75 (complex, 4H), 2.94-3.06 (complex, 2H), 3.36-3.58 (complex, 4H), 3.68 (t, J=5.49 Hz, 2H), 4.01-4.06 (complex, 1H), 4.14 (t, J=5.7 Hz, 2H), 4.22 (t, J=4.15 Hz, 2H), 6.71-7.08 (complex, 6H), 7.12 (d, J=8.4 Hz, 2H). COOH proton is too broad to observe.

EXAMPLE 52 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoic acid, sodium salt

The title compound (0.1 g, 52%) was prepared as a white hygroscopic solid from 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoic acid (0.18 g, 0.42 mmol) obtained in example 51 by an analogous procedure to that described in example 27.

¹H NMR (DMSO-₆, 200 MHz): δ 0.82 (t, J=5.72 Hz, 3H), 1.10-1.45 (complex, 8H), 2.75-2.96 (complex, 2H), 3.35-3.56 (complex, 4H), 3.67 (t, J=5.3 Hz, 2H), 4.08-4.21 (complex, 5H), 6.50-6.82 (complex, 6H), 7.12 (d, J=8.0 Hz, 2H).

EXAMPLE 53 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid

The title compound (0.1 g, 53%) was prepared as a colorless liquid from methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate (0.2 g, 0.461 mmol) obtained in example 19 by an analogous procedure to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 2.40-2.80 (bs, 1H, D₂O exchangeable), 3.22 (d, J=5.8 Hz, 2H), 3.49 (t, J=4.25 Hz, 2H), 3.67 (t, J=5.81 Hz, 2H), 4.14 (t, J=5.81 Hz, 2H), 4.21 (t, J=4.16 Hz, 2H), 4.82 (t, J=5.9 Hz, 1H), 6.61-7.02 (complex, 8H), 7.17-7.30 (complex, 5H).

EXAMPLE 54 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid

The title compound (0.2 g, 51%) was prepared as a gummy solid from methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate (0.4 g, 0.9 mmol) obtained in example 21 by a procedure analogous to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 3.02 (t, J=5.0 Hz, 2H), 3.22 (d, J 6.25 Hz, 2H), 3.68-3.78 (complex, 4H), 4.14 (t, J=5.81 Hz, 2H), 4.50 (t, J=6.19 Hz, 1H), 4.90-5.40 (b, 1H, D₂O exchangeable), 6.58-6.86 (complex, 7H), 6.94-7.07 (complex, 2H), 7.18-7.29 (complex, 4H).

EXAMPLE 55 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid, sodium salt

The title compound (0.05 g, 48%) was prepared as a hygroscopic solid from 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid (0.1 g, 0.24 mmol) obtained in example 53 by a procedure analogous to that described in example 27.

¹H NMR (DMSO-d₆, 200 MHz): δ 2.81-3.09 (complex, 2H), 3.42 (bs, 2H), 3.65 (t, J=4.5 Hz, 2H), 4.12 (bs, 4H), 4.22-4.32 (complex, 1H), 6.50-6.92 (complex, 8H), 7.10-7.33 (complex, 5H).

EXAMPLE 56 Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate

The title compound (0.27 g, 87%) was prepared as a syrupy liquid from methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate (0.3 g, 0.69 mmol) obtained in example 19 by an analogous procedure to that described in example 7.

¹H NMR (CDCl₃, 200 MHz): δ 1.39 (s, 3H), 3.09, 3.26 (1H each, 2d, J=13.7 Hz each), 3.51 (t, J=4.3 Hz, 2H), 3.66-3.73 (complex, 5H), 4.15 (t, J=5.5 Hz, 2H), 4.24 Hz, 2H), 6.61-7.01 (complex, 9 H), 7.12-7.22 (complex, 4H).

EXAMPLE 57 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid

The title compound (0.13 g, 50%) was prepared as a pale yellow hygroscopic solid from methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate (0.27 g, 0.60 mmol) obtained in example 56 by a procedure analogous to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 1.42 (s, 3H), 3.12, 3.29 (1H each, 2d, J=14.1 Hz each), 3.50 (t, J=4.5 Hz, 2H), 3.69 (t, J=5.6 Hz, 2H), 4.16 (t, J=5.81 Hz, 2H), 4.22 (t, J=4.5 Hz, 2H), 6.62-7.17 (complex, 9H), 7.21-7.30 (complex, 4H). COOH proton is too broad to observe.

EXAMPLE 58 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid, sodium salt

The title compound (0.055 g, 46%) was prepared as a hygroscopic pale yellow powder from 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid (0.13 g, 0.28 mmol) obtained in example 57 by a procedure analogous to that described in example 27.

¹H NMR (CDCl₃, 200 MHz): δ 1.15 (s, 3H), 2.99-3.21 (complex, 2H), 3.47 (bs, 2H), 3.67 (bs, 2H), 4.14 (bs, 4H), 6.53-6.9 (complex, 9H), 7.08-7.30 (complex, 4H).

EXAMPLE 59 Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate

The title compound (0.96 g, 93%) was prepared as a pale yellow liquid from methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate (1.0 g, 2.22 mmol) obtained in example 21 by an analogous procedure to that described in example 7.

¹H NMR (CDCl₃, 200 MHz): δ 1.40 (s, 3H), 3.03 (t, J=4.9 Hz, 2H), 3.09, 3.27 (1H each, 2d, J=13.7 Hz each), 3.70-3.85 (complex, 7H), 4.16 (t, J=5.81 Hz, 2H), 6.60-6.89 (complex, 6H), 6.96-7.30 (complex, 7H).

EXAMPLE 60 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid

The title compound (0.6 g, 65%) was prepared as a syrupy liquid from methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-yl)ethoxy]phenyl]-2-phenoxypropanoate (0.96 g, 2.00 mmol) obtained in example 59 by an analogous procedure to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 1.42 (s, 3H), 3.03 (t, J=5.0 Hz, 2H), 3.12, 3.30 (1H each, 2d, J=13.8 Hz each), 3.70-3.80 (complex, 4H), 4.15 (t, J=5.5 Hz, 2H), 6.58-7.08 (complex, 8H). 7.18-7.30 (complex, 5H), COOH proton is too broad to observe.

EXAMPLE 61 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate

The title compound (0.15 g, 38%) was prepared as a yellow liquid from 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid (0.3 g, 0.77 mmol) obtained in example 29 and 4-nitrophenol by an analogous procedure to that described in example 32.

¹H NMR (CDCl₃, 200MHz): δ 1.24 (t, J=6.92 Hz, 3H), 3.04 (t, J=5.16 Hz, 2H), 3.12 (d, J=6.63 Hz, 2H), 3.46-3.65 (complex, 1H), 3.70-3.86 (complex, 5H), 4.16 (t, J=5.23 Hz, 2H), 4.26 (t, J=5.5 Hz, 1H), 6.62-6.74 (complex, 2H), 6.84 (d, J=8.62 Hz, 2H), 6.94-7.22 (complex, 6H), 8.23 (d, J=9.0 Hz, 2H).

EXAMPLE 62 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid

The title compound (0.4 g, 57%) was prepared as a syrupy liquid from methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate (0.8 g, 2.16 mmol) obtained in example 25 by an analogous procedure to that described in example 26.

¹H NMR (CDCl₃, 200 MHz): δ 1.17 (t, J=7.0 Hz, 3H), 2.99-3.13 (complex, 2H), 3.31-3.65 (complex, 4H), 4.01-4.24 (complex, 3H, 4.45 (d, J=3.4 Hz, 2H), 4.52-4.59 (complex, 1H), 6.62-6.68 (complex, 6H), 7.14 (d, J=8.6 Hz, 2H), 7.27 (s, 5H). COOH proton is too broad to observe.

EXAMPLE 63 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid, sodium salt

The title compound (0.15 g, 75%) was prepared as a colorless hygroscopic solid from 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid (0.2 g, 0.44 mmol) obtained in example 62 by an analogous procedure to that described in example 27.

¹H NMR (DMSO-d₆, 200 MHz): δ 0.99 (t, J=6.97 Hz, 3H), 2.60-2.90 (complex, 2H), 3.30-3.65 (complex, 5H), 4.16 (d, J=5.0 Hz, 2H), 4.40-4.65 (complex, 3H), 6.55-6.89 (complex, 6H), 7.14 (d, J=8.5 Hz, 2H), 7.32 (s, 5H).

EXAMPLE 64 4-Nitrophenyl-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate

The title compound (0.6 g, 100%) was prepared as a dark brown liquid from 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid (0.5 g, 1.34 mmol) obtained in example 62 and 4-nitro phenol by a procedure analogous to that described in example 32.

¹H NMR (CDCl₃, 200 MHz): δ 1.25 (t, J=7.0 Hz, 3H), 3.14 (d, J=6.6 Hz, 2H), 3.33-3.55 (complex, 3H), 3.69-3.77 (complex, 1H), 4.05-4.31 (complex, 3H), 4.46 (d, J=3.4 Hz, 2H), 4.55-4.61 (complex, 1H), 6.63-6.68 (complex, 6H), 7.11-7.28 (complex, 7H), 7.52 (d, J=7.6 Hz, 2H), 8.23 (d, J=9.0 Hz, 2H).

The compounds of the present invention lowered random blood sugar level, triglyceride, total cholesterol, LDL, VLDL and increased HDL. This was demonstrated by in vitro as well as in vivo animal experiments.

Demonstration of Efficacy of Compounds

A) In Vitro:

a) Determination of hPPARα Activity:

Ligand binding domain of hPPARα was fused to DNA binding domain of Yeast transcription factor GAL4 in eucaryotic expression vector. Using superfect (Qiagen, Germany) as transfecting reagent HEK-293 cells were transfected with this plasmid and a reporter plasmid harboring the luciferase gene driven by a GAL4 specific promoter. Compound was added at different concentrations after 42 hrs of transfection and incubated overnight. Luciferase activity as a function of compound binding/activation capacity of PPARα was measured using Packard Luclite kit (Packard, USA) in Top Count (Ivan Sadowski, Brendan Bell, Peter Broag and Melvyn Hollis. Gene. 1992. 118: 137-141; Superfect Transfection Reagent Handbook. February, 1997. Qiagen, Germany).

b) Determination of hPPARγ Activity:

Ligand binding domain of hPPARγ1 was fused to DNA binding domain of Yeast transcription factor GAL4 in eucaryotic expression vector. Using lipofectamine (Gibco BRL, USA) as transfecting reagent HEK-293 cells were transfected with this plasmid and a reporter plasmid harboring the luciferase gene driven by a GAL4 specific promoter. Compound was added at 1 μM concentration after 48 hrs of transfection and incubated overnight. Luciferase activity as a function of drug binding/activation capacity of PPARγ1 was measured using Packard Luclite kit (Packard, USA) in Packard Top Count (Ivan Sadowski, Brendan Bell, Peter Broag and Melvyn Hollis. Gene. 1992. 118: 137-141; Guide to Eukaryotic Transfections with Cationic Lipid Reagents. Life Technologies, GIBCO BRL, USA).

c) Determination of HMG CoA Reductase Inhibition Activity:

Liver microsome bound reductase was prepared from 2% cholestyramine fed rats at mid-dark cycle. Spectrophotometric assays were carried out in 100 mM KH₂PO₄, 4 mM DTT, 0.2 mM NADPH, 0.3 mM HMG CoA and 125 μg of liver microsomal enzyme. Total reaction mixture volume was kept as 1 ml. Reaction was started by addition of HMG CoA. Reaction mixture was incubated at 37° C. for 30 min and decrease in absorbance at 340 nm was recorded. Reaction mixture without substrate was used as blank (Goldstein, J. L and Brown, M. S. Progress in understanding the LDL receptor and HMG CoA reductase, two membrane proteins that regulate the plasma cholesterol. J. Lipid Res. 1984, 25: 1450-1461). The test compounds inhibited the HMG CoA reductase enzyme.

B) In Vivo:

a) Efficacy in Genetic Models:

Mutation in colonies of laboratory animals and different sensitivities to dietary regimens have made the development of animal models with non-insulin dependent diabetes and hyperlipidemia associated with obesity and insulin resistance possible. Genetic models such as db/db and ob/ob (Diabetes, (1982) 31(1): 1-6) mice and zucker fa/fa rats have been developed by the various laboratories for understanding the pathophysiology of disease and testing the efficacy of new antidiabetic compounds (Diabetes, (1983) 32: 830-838; Annu. Rep. Sankyo Res. Lab. (1994). 46: 1-57). The homozygous animals, C57 BL/KsJ-db/db mice developed by Jackson Laboratory, US, are obese, hyperglycemic, hyperinsulinemic and insulin resistant (J. Clin. Invest., (1990) 85: 962-967), whereas heterozygous are lean and normoglycemic. In db/db model, mouse progressively develops insulinopenia with age, a feature commonly observed in late stages of human type II diabetes when blood sugar levels are insufficiently controlled. The state of pancreas and its course vary according to the models. Since this model resembles that of type II diabetes mellitus, the compounds of the present invention were tested for blood sugar and triglycerides lowering activities.

Male C57BL/KsJ-db/db mice of 8 to 14 weeks age, having body weight range of 35 to 60 grams, bred at Dr. Reddy's Research Foundation (DRF) animal house, were used in the experiment. The mice were provided with standard feed (National Institute of Nutrition (NIN), Hyderabad, India) and acidified water, ad libitum. The animals having more than 350 mg/dl blood sugar were used for testing. The number of animals in each group was 4.

Test compounds were suspended on 0.25% carboxymethyl cellulose and administered to test group at a dose of 0. 1 mg to 30 mg/kg through oral gavage daily for 6 days. The control group received vehicle (dose 10 ml/kg). On 6th day the blood samples were collected one hour after administration of test compounds/vehicle for assessing the biological activity.

The random blood sugar and triglyceride levels were measured by collecting blood (100 μl) through orbital sinus, using heparinised capillary in tubes containing EDTA which was centrifuged to obtain plasma. The plasma glucose and triglyceride levels were measured spectrometrically, by glucose oxidase and glycerol-3-PO₄ oxidase/peroxidase enzyme (Dr. Reddy's Lab. Diagnostic Division Kits, Hyderabad, India) methods respectively.

The blood sugar and triglycerides lowering activities of the test compound was calculated according to the formula.

No adverse effects were observed for any of the mentioned compounds of invention in the above test.

Reduction in Blood Triglyceride Dose Glucose Level Lowering Compound (mg/kg) (%) (%) Example 41 3 53 27 Example 50 3 45 23 Example 44 10  47 74

The ob/ob mice were obtained at 5 weeks of age from Bomholtgard, Demark and were used at 8 weeks of age. Zucker fa/fa fatty rats were obtained from IffaCredo, France at 10 weeks of age and were used at 13 weeks of age. The animals were maintained under 12 hour light and dark cycle at 25±1° C. Animals were given standard laboratory chow (NIN, Hyderabad, India) and water, ad libitum (Fujiwara, T., Yoshioka, S., Yoshioka, T., Ushiyama, I and Horikoshi, H. Characterization of new oral antidiabetic agent CS-045. Studies in KK and ob/ob mice and Zucker fatty rats. Diabetes. 1988. 37: 1549-1558).

The test compounds were administered at 0.1 to 30 mg/kg/day dose for 9 days. The control animals received the vehicle (0.25% carboxymethylcellulose, dose 10 ml/kg) through oral gavage.

The blood samples were collected in fed state 1 hour after drug administration on 0 and 9 day of treatment. The blood was collected from the retro-orbital sinus through heparinised capillary in EDTA containing tubes. After centrifugation, plasma sample was separated for triglyceride, glucose, free fatty acid, total cholesterol and insulin estimations. Measurement of plasma triglyceride, glucose, total cholesterol were done using commercial kits (Dr. Reddy's Laboratory, Diagnostic Division, India). The plasma free fatty acid was measured using a commercial kit from Boehringer Mannheim, Germany. The plasma insulin was measured using a RIA kit (BARC, India). The reduction of various parameters examined are calculated according to the formula given below.

In ob/ob mice oral glucose tolerance test was performed after 9 days treatment. Mice were fasted for 5 hrs and challenged with 3 gm/kg of glucose orally. The blood samples were collected at 0, 15, 30, 60 and 120 min for estimation of plasma glucose levels.

The experimental results from the db/db mice, ob/ob mice, Zucker fa/fa rats suggest that the novel compounds of the present invention also possess therapeutic utility as a prophylactic or regular treatment for diabetes, obesity, cardiovascular disorders such as hypertension, hyperlipidaemia and other diseases; as it is known from the literature that such diseases are interrelated to each other.

Blood glucose level and triglycerides are also lowered at doses greater than 10 mg/kg. Normally, the quantum of reduction is dose dependent and plateaus at certain dose.

b) Plasma triglyceride and Cholesterol Lowering Activity in Hypercholesterolemic Rat Models:

Male Sprague Dawley rats (NIN stock) were bred in DRF animal house. Animals were maintained under 12 hour light and dark cycle at 25±1° C. Rats of 180-200 gram body weight range were used for the experiment. Animals were made hypercholesterolemic by feeding 2% cholesterol and 1% sodium cholate mixed with standard laboratory chow [National Institute of Nutrition (NIN), Hyderabad, India] for 6 days. Throughout the experimental period the animals were maintained on the same diet (Petit, D., Bonnefis, M. T., Rey, C and Infante, R. Effects of ciprofibrate on liver lipids and lipoprotein synthesis in normo- and hyperlipidemic rats. Atherosclerosis. 1988. 74: 215-225).

The test compounds were administered orally at a dose 0.1 to 30 mg/kg/day for 3 days. Control group was treated with vehicle alone (0.25% Carboxymethylcellulose; dose 10 ml/kg).

The blood samples were collected in fed state 1 hour after drug administration on 0 and 3 day of compound treatment. The blood was collected from the retro-orbital sinus through heparinised capillary in EDTA containing tubes. After centrifugation, plasma sample was separated for total cholesterol, HDL and triglyceride estimations. Measurement of plasma triglyceride, total cholesterol and HDL were done using commercial kits (Dr. Reddy's Laboratory, Diagnostic Division, India). LDL and VLDL cholesterol were calculated from the data obtained for total cholesterol, HDL and triglyceride. The reduction of various parameters examined are calculated according to the formula.

Total Tri- Cho- Dose glyceride lesterol HDL LDL VLDL Example No. mg/kg (%) ↓ (%) ↓ (%) ↑ (%) ↓ (%) ↓ Example 27 1 43 57 37 58 79 Example 44 1 50 42 46 44 53 ↓ reduction; ↑ increase

c) Plasma triglyceride and Total Cholesterol Lowering Activity in Swiss Albino Mice and Guinea Pigs:

Male Swiss albino mice (SAM) and male Guinea pigs were obtained from NIN and housed in DRF animal house. All these animals were maintained under 12 hour light and dark cycle at 25±1° C. Animals were given standard laboratory chow (NIN, Hyderabad, India) and water, ad libitum. SAM of 20-25 g body weight range and Guinea pigs of 500-700 g body weight range were used (Oliver, P., Plancke, M. O., Marzin, D., Clavey, V., Sauzieres, J and Fruchart, J. C. Effects of fenofibrate, gemfibrozil and nicotinic acid on plasma lipoprotein levels in normal and hyperlipidemic mice. Atherosclerosis. 1988. 70: 107-114).

The test compounds were administered orally to Swiss albino mice at 0.3 to 30 mg/kg/day dose for 6 days. Control mice were treated with vehicle (0.25% Carboxymethylcellulose; dose 10 ml/kg). The test compounds were administered orally to Guinea pigs at 0.3 to 30 mg/kg/day dose for 6 days. Control animals were treated with vehicle (0.25% Carboxymethylcellulose; dose 5 ml/kg).

The blood samples were collected in fed state 1 hour after drug administration on 0 and 6 day of treatment. The blood was collected from the retro-orbital sinus through heparinised capillary in EDTA containing tubes. After centrifugation, plasma sample was separated for triglyceride and total cholesterol (Wieland, O. Methods of Enzymatic analysis. Bergermeyer, H. O., Ed., 1963. 211-214; Trinder, P. Ann. Clin. Biochem. 1969. 6: 24-27). Measurement of plasma triglyceride, total cholesterol and HDL were done using commercial kits (Dr. Reddy's Diagnostic Division, Hyderabad, India).

Triglyceride Dose Lowering Compound (mg/kg) (%) Example 33 3 55 Example 41 10  54 Example 43 3 49 Example 63 3 57

c) Body Weight Reducing Effect in Cholesterol Fed Hamsters:

Male Syrian Hamsters were procured from NIN, Hyderabad, India. Animals were housed at DRF animal house under 12 hour light and dark cycle at 25±1° C. with free access to food and water. Animals were maintained with 1% cholesterol containing standard laboratory chow (NIN) from the day of treatment.

The test compounds were administered orally at 1 to 30 mg/kg/day dose for 15 days. Control group animals were treated with vehicle (Mill Q water, dose 10 ml/kg/day). Body weights were measured on every 3^(rd) day.

Body weight Dose Reduction Example No. (mg/kg/day) (%) Example 27 10 12 Example 30 10 18

Formulae for Calculation:

1. Percent reduction in Blood sugar/triglycerides/total cholesterol/body weight were calculated according to the formula: $\text{Percent reduction~~(\%)} = {1 - {\frac{{TT}/{OT}}{{TC}/{OC}} \times 100}}$ OC = Zero day control group value OT = Zero day treated group value TC = Test day control group value TT = Test day treated group value

2. LDL and VLDL cholesterol levels were calculated according to the formula: $\text{LDL cholesterol in mg/dl} = {{{Total}\quad {cholesterol}} - {{HDL}\quad {cholesterol}} - \frac{Triglyceride}{5}}$

 VLDL cholesterol in mg/dl=Total cholesterol−HDL cholesterol−LDL cholesterol 

We claim:
 1. A compound of formula (I)

its tautomeric forms, its stereoisomers, its polymorphs, its pharmaceutically acceptable salts, or its pharmaceutically acceptable solvates, wherein the groups R¹, R², R³, R⁴, and the groups R⁵ and R⁶ when attached to a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy; wherein the heteroaralkyl moiety is as defined above; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino, aralkoxycarbonylamino, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides; one or both of R⁵ and R⁶ may represent an oxo group when attached to a carbon atom; R⁵ and R⁶ when attached to a nitrogen atom may be the same or different and represent hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy, wherein the heteroaralkyl moiety is as defined above; alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, esters or amides of carboxylic acid or esters or amides of sulfonic acid; X represents oxygen or sulfur; Ar represents an optionally substituted divalent single aromatic or fused aromatic or heterocyclic group; R⁷ represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, optionally substituted aralkyl group or forms a bond together with R⁸; R⁸ represents hydrogen, hydroxy, alkoxy, halogen, lower alkyl group, acyl, or optionally substituted aralkyl or R⁸ forms a bond together with R⁷; R⁹ represents hydrogen, or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acyl selected from acetyl, propionyl or benzoyl; heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; R¹⁰ represents hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl or oxazolethyl; Y represents oxygen or NR¹², where R¹² represents hydrogen, alkyl, aryl, hydroxyalkyl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl or oxazolethyl; R¹⁰ and R¹² together may form a 5 or 6 membered cyclic structure containing carbon atoms, which may optionally contain one or more heteroatoms selected from oxygen, sulfur or nitrogen; the linking group represented by —(CH₂)_(n)—(O)_(m)— may be attached either through a nitrogen atom or a carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or 1, with the proviso that when the linking group is attached through a carbon atom and either of R⁵ or R⁶ represents an oxo group and Y is an oxygen atom, R⁹ does not represent a hydrogen atom.
 2. A compound according to claim 1, wherein when the groups represented by R¹, R², R³ and R⁴, and the groups R⁵ and R⁶ when attached to a carbon atom are substituted, the substituents are selected from halogen, hydroxy, or nitro or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, aralkoxyalkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, arylamino, aminoalkyl, aryloxy, alkoxycarbonyl, alkylamino, alkoxyalkyl, alkylthio, thioalkyl, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides.
 3. A compound according to claim 1, wherein when the groups R⁵ and R⁶ attached to nitrogen are substituted, the substituents are selected from halogen atoms, hydroxy, acyl selected from acetyl, propionyl or benzoyl; acyloxy, or amino groups.
 4. A compound according to claim 1, wherein Ar represents optionally substituted divalent phenylene, naphthylene, pyridyl, quinolinyl, benzofuranyl, dihydrobenzofuryl, benzopyranyl, dihydrobenzopyranyl, indolyl, indolinyl, azaindolyl, azaindolinyl, pyrazolyl, benzothiazolyl, or benzoxazolyl groups.
 5. A compound according to claim 1, wherein when the group represented by R⁹ is substituted, the substituents are selected from halogen, hydroxy, or nitro or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, aralkoxyalkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, arylamino, aminoalkyl, aryloxy, alkoxycarbonyl, alkylamino, alkoxyalkyl, alkylthio, thioalkyl groups, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides.
 6. A compound selected from: Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (±) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (+) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (−) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; Ethyl (E/Z)-3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoate; Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (±) Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoate; (+) Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoate; (−) Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoate; (±) Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (+) Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (−) Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (±) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (+) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (−) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (±) Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (+) Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (−) Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; Ethyl (E/Z)-3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (±) Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (+) Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; (−) Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate; Ethyl (E/Z)-3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoate; (±) Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoate; (+) Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoate; (−) Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoate; (±) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate; (+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate; (−) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate; (±) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate; (+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate; (−) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoate; (±) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoate; (+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoate (−) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoate (±) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoate; (+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoate; (−) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoate; (±) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxy propanoate; (+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxy propanoate; (−) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxy propanoate; Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropenoate; (±) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (+) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (−) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; Ethyl (E/Z)-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropenoate; (±) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (+) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (−) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; Ethyl (E/Z)-3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate; (±) Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate; (+) Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate; (−) Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate; Ethyl (E/Z)-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate; (±) Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate; (+) Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate; (−) Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoate; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (±) 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts; (+) 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts; (−) 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts; (±) 3-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts; (+) 3-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts; (−) 3-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropanoic acid and its salts; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (±) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (+) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (−) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (±) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (+) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (−) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (±) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (+) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (−) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (±) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (+) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (−) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamide; (±) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (+) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (−) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (±) 2-(2-Fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (+) 2-(2-Fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (−) 2-(2-Fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (±) 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (+) 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (−) 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (±) 3-[4-[2-(3-Oxo-2H-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (+) 3-[4-[2-(3-Oxo-2H-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (−) 3-[4-[2-(3-Oxo-2H-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts; (±) 3-[6-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts; (+) 3-[6-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts; (−) 3-[6-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts; (±) 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts; (+) 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts; (−) 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoic acid and its salts; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoic acid and its salts; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoic acid and its salts; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropanoic acid and its salts; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid and its salts; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid and its salts; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid and its salts; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoic acid and its salts; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoic acid and its salts; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoic acid and its salts; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts; (±) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts; (+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts; (−) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts; (±) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (+) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (−) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (±) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts; (+) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts; (−) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts; (±) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (+) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (−) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoate; (±) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoic acid and its salts; (+) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoic acid and its salts; (−) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoic acid and its salts; (±) 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate; (+) 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate; (−) 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate; (±) 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid and its salts; (+) 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid and its salts; (−) 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxypropanoic acid and its salts; (±) 4-Nitrophenyl-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxy phenyl]-2-ethoxypropanoate; (+) 4-Nitrophenyl-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxy phenyl]-2-ethoxypropanoate; and (−) 4-Nitrophenyl-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxy phenyl]-2-ethoxypropanoate.
 7. A process for the preparation of a compound of formula (I)

its tautomeric forms, its stereoisomers, its polymorphs, its pharmaceutically acceptable salts, or its pharmaceutically acceptable solvates, wherein the groups R¹, R², R³, R⁴, and the groups R⁵ and R⁶ when attached to a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy; wherein the heteroaralkyl moiety is as defined above; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino, aralkoxycarbonylamino, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides; one or both of R⁵ and R⁶ may represent an oxo group when attached to a carbon atom; R⁵ and R⁶ when attached to a nitrogen atom may be the same or different and represent hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy, wherein the heteroaralkyl moiety is as defined above; alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, esters or amides of carboxylic acid or esters or amides of sulfonic acid; X represents oxygen or sulfur; Ar represents an optionally substituted divalent single aromatic or fused aromatic or heterocyclic group; R⁷ represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, optionally substituted aralkyl group or forms a bond together with R⁸; R⁸ represents hydrogen, hydroxy, alkoxy, halogen, lower alkyl group, acyl, or optionally substituted aralkyl or R⁸ forms a bond together with R⁷; R⁹ represents hydrogen, or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acyl selected from acetyl, propionyl or benzoyl; heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; R¹⁰ represents hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, helyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl or oxazolethyl; Y represents oxygen; the linking group represented by —(CH₂)_(n)—(O)_(m)— may be attached either through a nitrogen atom or a carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or 1, with the proviso that when the linking group is attached through a carbon atom and either of R⁵ or R⁶ represents an oxo group and Y is an oxygen atom, R⁹ does not represent a hydrogen atom which comprises: a) reacting a compound of the formula (IIIa)

where all symbols are as defined above with a compound of formula (IIIb)

where R⁹ and R¹⁰ are as defined above and R¹⁴ represents (C₁-C₆)alkyl, to yield compound of formula (IVa)

which represents a compound of formula (I) where R⁷ and R⁸ together represent a bond and Y represents an oxygen atom and all other symbols are as defined above, and (b) reducing the compound of formula (IVa) to yield a compound of the formula (I) where R⁷ and R⁸ each represent hydrogen atom and all symbols are as defined above.
 8. An intermediate of formula (IVf)

where the groups R¹, R², R³, R⁴, and the groups R⁵ and R⁶ when attached to a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy, wherein the heteroaralkyl moiety is as defined above; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino, aralkoxycarbonylamino, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides; one or both of R⁵ and R⁶ may represent an oxo group when attached to a carbon atom; R⁵ and R⁶ when attached to nitrogen atom may be the same or different and represent hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy wherein the heteroaralkyl moiety is as defined above; alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, esters or amides of carboxylic acid, or esters or amides of sulfonic acid; X represents oxygen or sulfur; Ar represents an optionally substituted divalent single aromatic or fused aromatic or heterocyclic group; R⁷ represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, or optionally substituted aralkyl group; R⁸ represents hydrogen, hydroxy, alkoxy, halogen, lower alkyl group, acyl selected from acetyl, propionyl or benzoyl; or optionally substituted aralkyl group; R⁹ represents hydrogen, or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acyl selected from acetyl, propionyl or benzoyl; heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; the linking group represented by —(CH₂)_(n)—(O)_(m)— may be attached either through a nitrogen atom or a carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or
 1. 9. A process for the preparation of compound of formula (IVf) as defined in claim 8 where R⁷ and R⁸ represent hydrogen atoms and all other symbols are as defined in claim 8 which comprises: a) reacting a compound of formula (IIIa)

where all symbols are as defined above with a compound of formula (IVh) R⁹OCH₂P⁺PPh₃ ⁻Hal  (IVh) where R⁹ represents optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acyl selected from acetyl, propionyl or benzoyl; heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl and Hal represents a halogen atom, to yield a compound of formula (IVi)

where all symbols are as defined above, b) reacting a compound of formula (IVi) with an alcohol of the formula R⁹OH where R⁹ is as defined above to yield a compound of formula (IVj),

where all symbols are as defined above, c) reacting a compound of formula (IVj) obtained above where all symbols are as defined above with trialkylsilyl cyanide to produce a compound of formula (IVf) where all symbols are as defined above.
 10. An intermediate of formula (IVg)

where the groups R¹, R², R³, R⁴, and the groups R⁵ and R⁶ when attached to a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; heteroaryloxy, wherein the heteroaryl moiety is as defined above; heteroaralkoxy, wherein the heteroaralkyl moiety is as defined above; acyl selected from acetyl, propionyl or benzoyl, acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino, aralkoxycarbonylamino, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides; one or both of R⁵ and R⁶ may represent an oxo group when attached to a carbon atom; R⁵ and R⁶ when attached to a nitrogen atom may be the same or different and represent hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy wherein the heteroalkyl moiety is as defined above; alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, esters or amides of carboxylic acid, or esters or amides of sulfonic acid; X represents oxygen or sulfur; Ar represents an optionally substituted divalent single aromatic or fused aromatic or heterocyclic group; R⁷ represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, or optionally substituted aralkyl group; R¹⁰ represents hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl or benzofuranyl; or heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; the linking group represented by —(CH₂)_(n)—(O)_(m)— may be attached either through a nitrogen atom or a carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or
 1. 11. A process for the preparation of compound of formula (IVg) defined in claim 10, which comprises: a) reacting a compound of formula (IIIh)

where L¹ is a leaving group and all other symbols are as defined in claim 10 with a compound of formula (IVl)

where R⁸ is a hydrogen atom and all other symbols are as defined in claim 10, to yield a compound of formula (IVk)

where R⁸ is a hydrogen atom and all other symbols are as defined above, and b) reacting a compound of formula (IVk) obtained above with a diazotizing agent.
 12. A pharmaceutical composition which comprises a compound of formula

as defined in claim 1 and a pharmaceutically acceptable carrier, diluent, excipient or solvent.
 13. A pharmaceutical composition as claimed in claim 12, in the form of a tablet, capsule, powder, syrup, solution or suspension.
 14. A pharmaceutical composition which comprises, a compound according to claim 6, as an active ingredient and a pharmaceutically acceptable carrier, diluent excipient or solvent.
 15. A pharmaceutical composition as claimed in claim 14, in the form of a tablet, capsule, powder, syrup, solution or suspension.
 16. 3-[4-[2-(2,3-Dihydro-1,4benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid of the formula:


17. A pharmaceutical composition which comprises a compound as defined in claim 16 and a pharmaceutically acceptable carrier, diluent, excipient or solvate.
 18. A pharmaceutical composition as claimed in claim 17 in the form of a tablet, capsule, powder, syrup, solution or suspension.
 19. A method of preventing or treating diabetes caused by insulin resistance or impaired glucose tolerance or complications of diabetes caused by insulin resistance or impaired glucose tolerance comprising administering a therapeutically effective amount of a compound of formula (I) as defined in claim 1 and a pharmaceutically acceptable carrier diluent or excipient to a patient in need thereof.
 20. The method according to claim 19, wherein the complication is dyslipidemia, hypertension, hyperglycemia, coronary heart disease, cardiovascular disorders, atherosclerosis , obesity, psoriasis, polycystic ovarian syndrome (PCOS), osteoporosis, hyperlipidemia, renal diseases, diabetic nephropathy, glomerulonephritis, glomerular sclerosis, nephrotic syndrome, hypertensive nephrosclerosis, end-stage renal disease, disorders related to endothelial cell division, microalbuminuria or eating disorders.
 21. A method of preventing or treating diabetes caused by insulin resistance or impaired glucose tolerance or complications of diabetes caused by insulin resistance or impaired glucose tolerance comprising administering a therapeutically effective amount of a compound of formula (I) as defined in claim 6, and a pharmaceutically acceptable carrier, diluent or excipient to a patient in need thereof.
 22. The method according to claim 21, wherein the complication is dyslipidaemia, hypertension, hyperglycemia, coronary heart disease, cardiovascular disorders, atherosclerosis, obesity, psoriasis, polycystic ovarian syndrome (PCOS), osteoporosis, hyperlipidemia, renal diseases, diabetic nephropathy, glomerulonephritis, glomerular sclerosis, nephrotic syndrome, hypertensive nephrosclerosis, end-stage renal disease, disorders related to endothelial cell division, microalbuminuria or eating disorders.
 23. A method of preventing or treating diabetes caused by insulin resistance or impaired glucose tolerance or complications of diabetes caused by insulin resistance or impaired glucose tolerance comprising administering a therapeutically effective amount of a compound of formula (I) as defined in claim 16, and a pharmaceutically acceptable carrier, diluent or excipient to a patient in need thereof.
 24. The method according to claim 23, wherein the complication is dyslipidaemia, hypertension, hyperglycemia, coronary heart disease, cardiovascular disorders, atherosclerosis, obesity, psoriasis, polycystic ovarian syndrome (PCOS), osteoporosis, hyperlipidemia, renal diseases diabetic nephropathy, glomerulonephritis, glomerular sclerosis, nephrotic syndrome, hypertensive nephrosclerosis, end-stage renal disease, disorders related to endothelial cell division, microalbuminuria or eating disorders.
 25. A method of reducing LDL, VLDL cholesterol, body weight, blood glucose, triglycerides, and free fatty acids comprising administering a compound as defined in claim 16 and a pharmaceutically acceptable carrier, diluent or solvates or excipient to a patient in need thereof.
 26. A method of reducing total cholesterol, body weight, blood plasma glucose, triglycerides, LDL, VLDL and free fatty acids in the plasma comprising administering a compound of formula (1), as defined in claim 1 and a pharmaceutically acceptable carrier, diluent, solvent or excipient to a patient in need thereof.
 27. A method of reducing total cholesterol, body weight, blood plasma glucose, triglycerides, LDL, VLDL and free fatty acids in the plasma comprising administering a compound of formula (1), as defined in claim 6 and a pharmaceutically acceptable carrier, diluent, solvent or excipient to a patient in need thereof. 